Fluid end

ABSTRACT

A fluid end comprising a plurality of fluid end sections positioned in a side-by-side relationship. Each fluid end section is releasably attached to a connect plate. Each connect plate is attached to a power source using a plurality of stay rods. Each fluid end section comprises a housing in fluid communication with a pair of intake manifolds and a discharge conduit. A fluid routing plug is installed within each housing and is configured to route fluid throughout the housing. A plunger is installed within stuffing box attached to each housing. A number of features, including the location of seals within bore walls and carbide inserts within valve guides, aid in reducing or transferring wear.

RELATED APPLICATIONS

This application is a Continuation of U.S. Ser. No. 17/838,362, authoredby Thomas et al., and filed on Jun. 13, 2022, which is a Continuation ofU.S. Ser. No. 17/515,707, authored by Thomas et al. and filed on Nov. 1,2021, which is a Continuation of U.S. Ser. No. 16/951,741, authored byThomas et al. and filed on Nov. 18, 2020, and also claims the benefit ofthe following provisional patent applications: Ser. No. 62/936,789,authored by Thomas et al. and filed on Nov. 18, 2019; Ser. No.62/940,513, authored by Thomas et al. and filed on Nov. 26, 2019; Ser.No. 62/953,763, authored by Thomas et al. and filed on Dec. 26, 2019;Ser. No. 62/957,489, authored by Foster et al. and filed on Jan. 6,2020; Ser. No. 62/959,570, authored by Thomas et al. and filed on Jan.10, 2020; Ser. No. 62/960,194, authored by Foster et al. and filed onJan. 13, 2020; Ser. No. 62/960,366, authored by Foster et al. and filedon Jan. 13, 2020; Ser. No. 62/968,634, authored by Foster et al. andfiled on Jan. 31, 2020; Ser. No. 62/990,817, authored by Thomas et al.and filed on Mar. 17, 2020; Ser. No. 63/008,036, authored by Thomas etal. and filed on Apr. 10, 2020; Ser. No. 63/018,021, authored by Thomaset al. and filed Apr. 30, 2020; Ser. No. 63/019,789, authored by Thomaset al. and filed on May 4, 2020; Ser. No. 63/027,584, authored by Thomaset al. and filed on May 20, 2020; Ser. No. 63/033,244, authored byThomas et al. and filed Jun. 2, 2020; Ser. No. 63/040,086, authored byThomas et al. and filed on Jun. 17, 2020; Ser. No. 63/046,826, authoredby Thomas et al. and filed on Jul. 1, 2020; Ser. No. 63/053,797,authored by Thomas et al. and filed on Jul. 20, 2020; Ser. No.63/076,587, authored by Thomas et al. and filed on Sep. 10, 2020; andSer. No. 63/089,882, authored by Thomas et al. and filed on Oct. 9,2020. The entire contents of all of the above listed provisional patentapplications are incorporated herein by reference.

BACKGROUND

Various industrial applications may require the delivery of high volumesof highly pressurized fluids. For example, hydraulic fracturing(commonly referred to as “fracking”) is a well stimulation techniqueused in oil and gas production, in which highly pressurized fluid isinjected into a cased wellbore. As shown for example in FIG. 1 , thepressured fluid flows through perforations 10 in a casing 12 and createsfractures 14 in deep rock formations 16. Pressurized fluid is deliveredto the casing 12 through a wellhead 18 supported on the ground surface20. Sand or other small particles (commonly referred to as “proppants”)are normally delivered with the fluid into the rock formations 16. Theproppants help hold the fractures 14 open after the fluid is withdrawn.The resulting fractures 14 facilitate the extraction of oil, gas, brine,or other fluid trapped within the rock formations 16.

Fluid ends are devices used in conjunction with a power source topressurize the fluid used during hydraulic fracturing operations. Asingle fracking operation may require the use of two or more fluid endsat one time. For example, six fluid ends 22 are shown operating at awellsite 24 in FIG. 2 . Each of the fluid ends 22 is attached to a powerend 26 in a one-to-one relationship. The power end 26 serves as anengine or motor for the fluid end 22. Together, the fluid end 22 andpower end 26 function as a hydraulic pump.

Continuing with FIG. 2 , a single fluid end 22 and its correspondingpower end 26 are typically positioned on a truck bed 28 at the wellsite24 so that they may be easily moved, as needed. The fluid and proppantmixture to be pressurized is normally held in large tanks 30 at thewellsite 24. An intake piping system 32 delivers the fluid and proppantmixture from the tanks 30 to each fluid end 22. A discharge pipingsystem 33 transfers the pressurized fluid from each fluid end 22 to thewellhead 18, where it is delivered into the casing 12 shown in FIG. 1 .

Fluid ends operate under notoriously extreme conditions, enduring thesame pressures, vibrations, and abrasives that are needed to fracturethe deep rock formations shown in FIG. 1 . Fluid ends may operate atpressures of 5,000-15,000 pounds per square inch (psi) or greater. Fluidused in hydraulic fracturing operations is typically pumped through thefluid end at a pressure of at least 8,000 psi, and more typicallybetween 10,000 and 15,000 psi. However, the pressure may reach up to22,500 psi. The power end used with the fluid end typically has a poweroutput of at least 2,250 horsepower during hydraulic fracturingoperations. A single fluid end typically produces a fluid volume ofabout 400 gallons, or 10 barrels, per minute during a frackingoperation. A single fluid end may operate in flow ranges from 170 to 630gallons per minute, or approximately 4 to 15 barrels per minute. When aplurality of fluid ends are used together, the fluid ends collectivelydeliver about 4,200 gallons per minute or 100 barrels per minute to thewellbore.

In contrast, mud pumps known in the art typically operate at a pressureof less than 8,000 psi. Mud pumps are used to deliver drilling mud to arotating drill bit within the wellbore during drilling operations. Thus,the drilling mud does not need to have as high of fluid pressure asfracking fluid. A fluid end does not pump drilling mud. A power end usedwith mud pumps typically has a power output of less than 2,250horsepower. Mud pumps generally produce a fluid volume of about 150-600gallons per minute, depending on the size of pump used.

In further contrast, a fluid jetting pump known in the art typicallyoperates at pressures of 30,000-90,000 psi. Jet pumps are used todeliver a highly concentrated stream of fluid to a desired area. Jetpumps typically deliver fluid through a wand. Fluid ends do not deliverfluid through a wand. Unlike fluid ends, jet pumps are not used inconcert with a plurality of other jet pumps. Rather, only a single jetpump is used to pressurize fluid. A power end used with a jet pumptypically has a power output of about 1,000 horsepower. Jet pumpsgenerally produce a fluid volume of about 10 gallons per minute.

High operational pressures may cause a fluid end to expand or crack.Such a structural failure may lead to fluid leakage, which leaves thefluid end unable to produce and maintain adequate fluid pressures.Moreover, if proppants are included in the pressurized fluid, thoseproppants may cause erosion at weak points within the fluid end,resulting in additional failures.

It is not uncommon for conventional fluid ends to experience failureafter only several hundred operating hours. Yet, a single frackingoperation may require as many as fifty (50) hours of fluid endoperation. Thus, a traditional fluid end may require replacement afteruse on as few as two fracking jobs.

During operation of a hydraulic pump, the power end is not exposed tothe same corrosive and abrasive fluids that move through the fluid end.Thus, power ends typically have much longer lifespans than fluid ends. Atypical power end may service five or more different fluid ends duringits lifespan.

With reference to FIG. 3 , a traditional power end 34 is shown. Thepower end 34 comprises a housing 36 having a mounting plate 38 formed onits front end 40. A plurality of stay rods 42 are attached to andproject from the mounting plate 38. A plurality of pony rods 44 aredisposed at least partially within the power end 34 and project fromopenings formed in the mounting plate 38. Each of the pony rods 44 isattached to a crank shaft installed within the housing 36. Rotation ofthe crank shaft powers reciprocal motion of the pony rods 44 relative tothe mounting plate 38.

A fluid end 46 shown in FIG. 3 is attached to the power end 34. Thefluid end 46 comprises a single housing 48 having a flange 50 machinedtherein. The flange 50 provides a connection point for the plurality ofstay rods 42. The stay rods 42 rigidly interconnect the power end 34 andthe fluid end 46. When connected, the fluid end 46 is suspended inoffset relationship to the power end 34.

A plurality of plungers 52 are disposed within the fluid end 46 andproject from openings formed in the flange 50. The plungers 52 and ponyrods 44 are arranged in a one-to-one relationship, with each plunger 52aligned with and connected to a corresponding one of the pony rods 44.Reciprocation of each pony rod 44 causes its connected plunger 52 toreciprocate within the fluid end 46. In operation, reciprocation of theplungers 52 pressurizes fluid within the fluid end 46. The reciprocationcycle of each plunger 52 is differently phased from that of eachadjacent plunger 52.

With reference to FIG. 5 , the interior of the fluid end 46 includes aplurality of longitudinally spaced bore pairs. Each bore pair includes avertical bore 56 and an intersecting horizontal bore 58. The zone ofintersection between the paired bores defines an internal chamber 60.Each plunger 52 extends through a horizontal bore 58 and into itsassociated internal chamber 60. The plungers 52 and horizontal bores 58are arranged in a one-to-one relationship.

Each horizontal bore 58 is sized to receive a plurality of packing seals64. The seals 64 are configured to surround the installed plunger 52 andprevent high-pressure fluid from passing around the plunger 52 duringoperation. The packing seals 64 are maintained within the bore 58 by aretainer 65. The retainer 65 has external threads 63 that mate withinternal threads 67 formed in the walls surrounding the bore 58. In sometraditional fluid ends, the packing seals 64 are installed within aremovable stuffing box sleeve that is installed within the horizontalbore.

Each vertical bore 56 interconnects opposing top and bottom surfaces 66and 68 of the fluid end 46. Each horizontal bore 58 interconnectsopposing front and rear surfaces 70 and 72 of the fluid end 46. Adischarge plug 74 seals each opening of each vertical bore 56 on the topsurface 66 of the fluid end 46. Likewise, a suction plug 76 seals eachopening of each horizontal bore 58 on the front surface 70 of the fluidend 46.

Each of the plugs 74 and 76 features a generally cylindrical body. Anannular seal 77 is installed within a recess formed in an outer surfaceof that body, and blocks passage of high pressure fluid. The dischargeand suction plugs 74 and 76 are retained within their correspondingbores 56 and 58 by a retainer 78, shown in FIGS. 3, 5, and 6 . Theretainer 78 has a cylindrical body having external threads 79 formed inits outer surface. The external threads 79 mate with internal threads 81formed in the walls surrounding the bore 56 or 58 between the installedplug 74 or 76 and the surface 66 or 70 of the fluid end 46.

As shown in FIG. 3 , a single manifold 80 is attached to the fluid end46. The manifold 80 is also connected to an intake piping system, of thetype shown in FIG. 2 . Fluid to be pressurized is drawn from the intakepiping system into the manifold 80, which directs the fluid into each ofthe vertical bores 56, by way of openings (not shown) in the bottomsurface 68.

When a plunger 52 is retracted, fluid is drawn into each internalchamber 60 from the manifold 80. When a plunger 52 is extended, fluidwithin each internal chamber 60 is pressurized and forced towards adischarge conduit 82. Pressurized fluid exits the fluid end 46 throughone or more discharge openings 84, shown in FIGS. 3-5 . The dischargeopenings 84 are in fluid communication with the discharge conduit 82.The discharge openings 84 are attached to a discharge piping system, ofthe type shown in FIG. 2 .

A pair of valves 86 and 88 are installed within each vertical bore 56,on opposite sides of the internal chamber 60. The valve 86 preventsbackflow in the direction of the manifold 80, while the valve 88prevents backflow in the direction of the internal chamber 60. Thevalves 86 and 88 each comprise a valve body 87 that seals against avalve seat 89.

Traditional fluid ends are normally machined from high strength alloysteel. Such material can corrode quickly, leading to fatigue cracks.Fatigue cracks occur because corrosion of the metal decreases themetal's fatigue strength—the amount of loading cycles that can beapplied to a metal before it fails. Such cracking can allow leakage thatprevents a fluid end from achieving and maintaining adequate pressures.Once such leakage occurs, fluid end repair or replacement becomesnecessary.

Fatigue cracks in fluid ends are commonly found in areas that experiencehigh stress. For example, with reference to the fluid end 46 shown inFIG. 5 , fatigue cracks are common at a corner 90 formed in the interiorof the fluid end 46 by the intersection of the walls surrounding thehorizontal bore 58 with the walls surrounding the vertical bore 56. Aplurality of the corners 90 surround each internal chamber 60. Becausefluid is pressurized within each internal chamber 60, the corners 90typically experience the highest amount of stress during operation,leading to fatigue cracks. Fatigue cracks are also common at the neckthat connects the flange 50 and the housing 48. Specifically, fatiguecracks tend to form at an area 92 where the neck joins the housing 48,as shown for example in FIGS. 4 and 5 .

For the above reasons, there is a need in the industry for a fluid endconfigured to avoid or significantly delay the structures or conditionsthat cause wear or failures within a fluid end.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of the underground environment of a hydraulicfracturing operation.

FIG. 2 illustrates above-ground equipment used in a hydraulic fracturingoperation.

FIG. 3 is a left side perspective view of a traditional fluid endattached to a traditional power end.

FIG. 4 is a top plan view of the fluid end shown in FIG. 3 .

FIG. 5 is a sectional view of the fluid end shown in FIG. 4 , takenalong line A-A.

FIG. 6 is a front perspective view of a fluid end. A plurality of stayrods are attached to the fluid end.

FIG. 7 is a rear perspective view of the fluid end shown in FIG. 6 , butthe plurality of stay rods have been removed.

FIG. 7A is a side elevational view of the fluid end shown in FIG. 6 ,but with another embodiment of intake and discharge manifolds.

FIG. 7B is a front perspective view of the fluid end shown in FIG. 7A.

FIG. 8 is a front perspective view of one of the fluid end sectionsmaking up the fluid end shown in FIG. 6 .

FIG. 9 is a cross-sectional view of the fluid end section shown in FIG.8 , taken along line D-D.

FIG. 10 is a perspective view of a first surface of a connect plate usedwith the fluid end shown in FIG. 6 .

FIG. 11 is a perspective view of a second surface of the connect plateshown in FIG. 10 .

FIG. 12 is an elevational view of the first surface of the connect plateshown in FIG. 10 .

FIG. 13 is an elevational view of the second surface of the connectplate shown in FIG. 10 .

FIG. 14 is a perspective view of a second surface of a housing making upthe fluid end section shown in FIG. 8 .

FIG. 15 is an elevational view of the second surface of the housingshown in FIG. 14 .

FIG. 16 is a cross-sectional view of the fluid end and stay rods shownin FIG. 6 , taken along a plane that includes the line B-B.

FIG. 17 is a cross-sectional view of the fluid end and stay rods shownin FIG. 6 , taken along a plane that includes the line C-C.

FIG. 18 is a top plan view of the housing shown in FIG. 14 .

FIG. 19 is an enlarged view of area E shown in FIG. 9 .

FIG. 20 is the cross-sectional view of the fluid end section shown inFIG. 17 with the upper and lower intake manifolds shown attached to thehousing.

FIG. 21 is a rear perspective view of the fluid end section shown inFIG. 20 , but the plunger has been removed.

FIG. 22 is a top plan view of a stuffing box shown attached to thehousing in FIG. 20 .

FIG. 23 is a perspective view of a first surface of the stuffing boxshown in FIG. 22 .

FIG. 24 is an elevational view of the first surface of the stuffing boxshown in FIG. 22 .

FIG. 25 is a cross-sectional view of the stuffing box shown in FIG. 24 ,taken along line F-F.

FIG. 26 is a cross-sectional view of the stuffing box shown in FIG. 24 ,taken along line G-G.

FIG. 27 is a perspective view of a second surface of the stuffing boxshown in FIG. 22 .

FIG. 28 is an elevational view of the second surface of the stuffing boxshown in FIG. 22 .

FIG. 29 is a cross-sectional view of the stuffing box shown in FIG. 28 ,taken along line H-H.

FIG. 30 is a top plan view of a retainer shown attached to the stuffingbox in FIG. 20 .

FIG. 31 is a perspective view of a first surface of the retainer shownin FIG. 30 .

FIG. 32 is an elevational view of the first surface of the retainershown in FIG. 30 .

FIG. 33 is a cross-sectional view of the retainer shown in FIG. 32 ,taken along line I-I.

FIG. 34 is a cross-sectional view of the retainer shown in FIG. 36 ,taken along line J-J.

FIG. 35 is a perspective view of a second surface of the retainer shownin FIG. 30 .

FIG. 36 is an elevational view of the second surface of the retainershown in FIG. 30 .

FIG. 37 is a cross-sectional view of the retainer shown in FIG. 36 ,taken along line K-K.

FIG. 38 is a top plan view of a plunger packing shown installed withinthe stuffing box and retainer in FIG. 20 .

FIG. 39 is a perspective view of a first surface of the plunger packingshown in FIG. 38 .

FIG. 40 is an elevational view of the first surface of the plungerpacking shown in FIG. 38 .

FIG. 41 is a cross-sectional view of the plunger packing shown in FIG.40 , taken along line L-L.

FIG. 42 is a perspective exploded view of the plunger packing shown inFIG. 38 .

FIG. 43 is a top plan view of a packing nut shown installed within theretainer in FIG. 20 .

FIG. 44 is a perspective view of a first surface of the packing nutshown in FIG. 43 .

FIG. 45 is an elevational view of the first surface of the packing nutshown in FIG. 43 .

FIG. 46 is a cross-sectional view of the packing nut shown in FIG. 45 ,taken along line M-M.

FIG. 47 is a perspective view of a first surface of a retainer showninstalled within the housing in FIG. 20 .

FIG. 48 is an elevational view of the first surface of the retainershown in FIG. 47 .

FIG. 49 is a cross-sectional view of the retainer shown in FIG. 48 ,taken along line N-N.

FIG. 50 is the cross-sectional view shown in FIG. 9 , but the suctionvalve is spaced from the fluid routing plug.

FIG. 51 is the cross-sectional view shown in FIG. 50 , but the plungerhas extended into the housing, the suction valve is sealed against thefluid routing plug, and the discharge valve is spaced from the fluidrouting plug.

FIG. 52 is a perspective view of a second surface of a fluid routingplug shown installed within the fluid end section in FIG. 50 .

FIG. 53 is a perspective view of a first surface of the fluid routingplug shown in FIG. 52 .

FIG. 54 is an elevational view of the second surface of the fluidrouting plug shown in FIG. 52 .

FIG. 55 is a cross-sectional view of the fluid routing plug shown inFIG. 54 , taken along line O-O.

FIG. 56 is an elevational view of the first surface of the fluid routingplug shown in FIG. 52 .

FIG. 57 is a top plan view of the fluid routing plug shown in FIG. 52 .

FIG. 58 is a cross-sectional view of the fluid routing plug shown inFIG. 57 , taken along line P-P.

FIG. 59 is an enlarged view of area Q shown in FIG. 57 .

FIG. 60 is the top plan view of the fluid routing plug shown in FIG. 57, but the plug has been slightly rotated.

FIG. 61 is a cross-sectional view of the fluid routing plug shown inFIG. 60 , taken along line R-R.

FIG. 62 is a cross-sectional view of the fluid routing plug shown inFIG. 60 , taken along line S-S.

FIG. 63 is a cross-sectional view of the fluid routing plug shown inFIG. 60 , taken along line T-T.

FIG. 64 is an enlarged view of the fluid routing plug shown in FIG. 60 .

FIG. 65 is the cross-sectional view shown in FIG. 50 .

FIG. 66 is an enlarged view of area U shown in FIG. 65 .

FIG. 67 is an enlarged view of area V shown in FIG. 65 .

FIG. 68 is an enlarged view of area W shown in FIG. 65 .

FIG. 69 is an enlarged view of area X shown in FIG. 65 .

FIG. 70 is an enlarged view of area Y shown in FIG. 65 .

FIG. 71 is an enlarged view of area Z shown in FIG. 65 .

FIG. 72 is a top plan view of a suction valve shown installed within thehousing in FIG. 50 .

FIG. 73 is a perspective view of a second surface of the suction valveshown in FIG. 72 .

FIG. 74 is an elevational view of the second surface of the suctionvalve shown in FIG. 72 .

FIG. 75 is a perspective view of a first surface of the suction valveshown in FIG. 72 .

FIG. 76 is a cross-sectional view of the suction valve shown in FIG. 74, taken along line AA-AA.

FIG. 77 is a top plan view of a suction valve guide shown installedwithin the housing shown in FIG. 50 .

FIG. 78 is a perspective view of a first surface of the suction valveguide shown in FIG. 77 .

FIG. 79 is an elevation view of the first surface of the suction valveguide shown in FIG. 77 .

FIG. 80 is a cross-sectional view of the suction valve guide shown inFIG. 79 , taken along line AB-AB.

FIG. 81 is a perspective view of a second surface of the suction valveguide shown in FIG. 77 .

FIG. 82 is an elevational view of the second surface of the suctionvalve guide shown in FIG. 77 .

FIG. 83 is a perspective view of the suction valve guide shown in FIG.77 engaged with the suction valve shown in FIG. 72 . A spring is shownpositioned between the suction valve guide and the suction valve.

FIG. 84 is a top plan view of the suction valve guide, suction valve,and spring shown in FIG. 83 .

FIG. 85 is a top plan view of a discharge valve shown installed withinthe housing in FIG. 50 .

FIG. 86 is a perspective view of a second surface of the discharge valveshown in FIG. 85 .

FIG. 87 is an elevational view of the second surface of the dischargevalve shown in FIG. 85 .

FIG. 88 is a perspective view of a first surface of the discharge valveshown in FIG. 85 .

FIG. 89 is a cross-sectional view of the discharge valve shown in FIG.87 , taken along line AC-AC.

FIG. 90 is a top plan view of a discharge valve guide shown installedwithin the housing in FIG. 50 .

FIG. 91 is a perspective view of a first surface of the discharge valveguide shown in FIG. 90 .

FIG. 92 is an elevation view of the first surface of the discharge valveguide shown in FIG. 90 .

FIG. 93 is a cross-sectional view of the discharge valve guide shown inFIG. 92 , taken along line AD-AD.

FIG. 94 is a cross-sectional view of the discharge valve guide shown inFIG. 92 , taken along line AE-AE.

FIG. 95 is a perspective view of a second surface of the discharge valveguide shown in FIG. 90 .

FIG. 96 is a perspective cut-away view of a first surface of the fluidend section shown in FIG. 8 .

FIG. 97 is an enlarged view of area AF shown in FIG. 96 .

FIG. 98 is a perspective view of the discharge valve guide shown in FIG.90 engaged with the discharge valve shown in FIG. 85 . A spring is shownpositioned between the discharge valve guide and the discharge valve.

FIG. 99 is a top plan view of the discharge valve guide, dischargevalve, and spring shown in FIG. 98 .

FIG. 100 is the cross-sectional view of the fluid end section shown inFIG. 9 .

FIG. 100A is a perspective view of a second surface of anotherembodiment of a fluid routing plug.

FIG. 10B is a perspective view of a first surface of the fluid routingplug shown in FIG. 100A.

FIG. 100C is an elevational view of the second surface of the fluidrouting plug shown in FIG. 100A.

FIG. 100D is a cross-sectional view of the fluid routing plug shown inFIG. 100C, taken along line JA-JA.

FIG. 100E is a cross-sectional view of the fluid routing plug shown inFIG. 100C, taken along line JB-JB.

FIG. 100F is the cross-sectional view of the fluid end section shown inFIG. 9 , but the fluid routing plug from FIG. 100A is shown installedwithin the housing.

FIG. 100G is an enlarged view of area JC from FIG. 100F.

FIG. 101 is a perspective view of a first surface of another embodimentof a fluid routing plug.

FIG. 102 is an elevational view of the first surface of the fluidrouting plug shown in FIG. 101 .

FIG. 103 is a cross-sectional view of the fluid routing plug shown inFIG. 102 , taken along line AG-AG.

FIG. 104 is a top plan view of the fluid routing plug shown in FIG. 101.

FIG. 105 is a perspective view of a second surface of the fluid routingplug shown in FIG. 101 .

FIG. 106 is an elevational view of the second surface of the fluidrouting plug shown in FIG. 101 .

FIG. 107 is a cross-sectional view of the fluid routing plug shown inFIG. 106 , taken along line AH-AH.

FIG. 108 is the cross-sectional view of the fluid end section shown inFIG. 50 , but the fluid routing plug from FIG. 101 is shown installedwithin the housing.

FIG. 109 is the cross-sectional view of the fluid end section shown inFIG. 51 , but the fluid routing plug from FIG. 101 is shown installedwithin the housing.

FIG. 110 is a top plan view of another embodiment of a suction anddischarge valve.

FIG. 111 is a perspective view of a second surface of the suction anddischarge valve shown in FIG. 110 .

FIG. 112 is an elevational view of a second surface of the suction anddischarge valve shown in FIG. 110 .

FIG. 113 is a perspective view of a first surface of the suction anddischarge valve shown in FIG. 110 .

FIG. 114 is a cross-sectional view of the suction and discharge valveshown in FIG. 112 , taken along line AI-AI.

FIG. 115 is the cross-sectional view of the fluid end section shown inFIG. 65 , but another embodiment of a fluid routing plug is showninstalled within the housing.

FIG. 116 is an enlarged view of area AJ shown in FIG. 115 .

FIG. 117 is an enlarged view of area AK shown in FIG. 115 .

FIG. 118 is the cross-sectional view of the fluid end section shown inFIG. 65 , but another embodiment of a fluid routing plug is showninstalled within the housing.

FIG. 119 is an enlarged view of area AL shown in FIG. 118 .

FIG. 120 is an enlarged view of area AM shown in FIG. 118 .

FIG. 121 is a top plan view of another embodiment of a fluid routingplug.

FIG. 122 is a perspective view of a second surface of the fluid routingplug shown in FIG. 121 , with a plurality of second fluid passagesformed within the plug shown by phantom lines.

FIG. 123 is an elevational view of the second surface of the fluidrouting plug shown in FIG. 121 , with a plurality of second fluidpassages formed within the plug shown by phantom lines.

FIG. 124 is a cross-sectional view of the fluid routing plug shown inFIG. 123 , taken along line AN-AN.

FIG. 125 is a cross-sectional view of the fluid routing plug shown inFIG. 121 , taken along line AO-AO.

FIG. 126 is the top plan view of the fluid routing plug shown in FIG.121 , with the plurality of second fluid passages formed within the plugshown by phantom lines.

FIG. 127 is an elevational view of a first surface of the fluid routingplug shown in FIG. 121 , with a plurality of second fluid passagesformed within the plug shown by phantom lines.

FIG. 128 is a perspective view of the first surface of the fluid routingplug shown in FIG. 121 .

FIG. 128A is a perspective view of a second surface of anotherembodiment of a fluid routing plug.

FIG. 128B is an elevational view of the second surface of the fluidrouting plug shown in FIG. 128A.

FIG. 128C is a cross-sectional view of the fluid routing plug shown inFIG. 128A, taken along line KA-KA.

FIG. 128D is a top plan view of the fluid routing plug shown in FIG.128A.

FIG. 128E is a perspective view of a first surface of the fluid routingplug shown in FIG. 128A.

FIG. 128F is an elevational view of the first surface of the fluidrouting plug shown in FIG. 128A.

FIG. 128G is a cross-sectional view of the fluid routing plug shown inFIG. 128D, taken along line KB-KB.

FIG. 129 is a top plan view of another embodiment of a fluid routingplug.

FIG. 130 is an elevational view of a second surface of the fluid routingplug shown in FIG. 129 .

FIG. 131 is a cross-sectional view of the fluid routing plug shown inFIG. 130 , taken along line AP-AP.

FIG. 132 is a perspective view of a first surface of another embodimentof a fluid end section having another embodiment of a housing.

FIG. 133 is a cross-sectional view of the fluid end section shown inFIG. 132 , taken along a plane positioned on line AQ-AQ.

FIG. 134 is a top plan view of a retainer shown attached to the housingin FIG. 132 .

FIG. 135 a perspective view of a second surface of the retainer shown inFIG. 134 .

FIG. 136 is an elevational view of the first surface of the retainershown in FIG. 134 .

FIG. 137 is a cross-sectional view of the retainer shown in FIG. 135 ,taken along line AR-AR.

FIG. 138 is a perspective view of a first surface of the housing shownin FIG. 132 .

FIG. 139 is an enlarged view of area AS shown in FIG. 138 .

FIG. 140 is a sectional view of another embodiment of a fluid endsection.

FIG. 141 is a sectional view of the fluid end section shown in FIG. 140, taken along a different axis.

FIG. 142 is a top plan view of a first section of the housing shown inFIG. 140 .

FIG. 143 is a perspective view of a first surface of the first sectionshown in FIG. 142 .

FIG. 144 is an elevational view of the first surface of the firstsection shown in FIG. 142 .

FIG. 145 is a cross-sectional view of the first section shown in FIG.144 taken along line AT-AT.

FIG. 146 is a perspective view of a second surface of the first sectionshown in FIG. 142 .

FIG. 147 is an elevational view of the second surface of the firstsection shown in FIG. 142 .

FIG. 148 is a cross-sectional view of the first section shown in FIG.147 , taken along line AU-AU.

FIG. 149 is a perspective view of a first surface of a second section ofa housing shown in FIG. 140 .

FIG. 150 is an elevational view of the first surface of the secondsection shown in FIG. 149 .

FIG. 151 is a cross-sectional view of the second section shown in FIG.150 , taken along line AV-AV.

FIG. 152 is a cross-sectional view of the second section shown in FIG.150 , taken along line AW-AW.

FIG. 153 is a sectional view of another embodiment of a fluid endsection.

FIG. 154 is a perspective view of a first surface of a housing of thefluid end section shown in FIG. 153 .

FIG. 155 is a top plan view of the housing shown in FIG. 154 .

FIG. 156 is an elevational view of the first surface of the housingshown in FIG. 154 .

FIG. 157 is a side elevational view of the housing shown in FIG. 154 .

FIG. 158 is a side elevational view of the fluid end section shown inFIG. 153 .

FIG. 159 is a cross-sectional view of the fluid end section shown inFIG. 158 , taken along line AX-AX.

FIG. 160 is a sectional view of the fluid end section shown in FIG. 153, taken along a different axis.

FIG. 161 is an enlarged view of area AY shown in FIG. 160 .

FIG. 162 is an elevational view of a first surface of another embodimentof a stuffing box of the fluid end section in FIG. 153 .

FIG. 163 is a perspective view of the first surface of the stuffing boxshown in FIG. 162 .

FIG. 164 is a top plan view of the stuffing box shown in FIG. 162 .

FIG. 165 is a cross-sectional view of the stuffing box shown in FIG. 162, taken along line AZ-AZ.

FIG. 166 is a perspective view of a second surface of another embodimentof a fluid end section.

FIG. 167 is a cross-sectional view of the fluid end section shown inFIG. 166 , taken along a plane positioned on line BA-BA.

DETAILED DESCRIPTION

Turning now to the non-prior art figures, FIGS. 6 and 7 show a fluid end100. The fluid end 100 may be attached to the traditional power end 34,shown in FIG. 3 . Alternatively, the fluid end 100 may be attached tovarious embodiments of power ends, such as the modular power enddescribed in U.S. Provisional Patent Application Ser. No. 63/053,797,authored by Thomas et al. and filed on Jul. 20, 2020.

Unlike the traditional fluid end 46, shown in FIG. 3 , the fluid end 100comprises a plurality of fluid end sections 102 rather than a singlehousing 48. The fluid end sections 102 are positioned in a side-by-siderelationship. Preferably, the fluid end 100 comprises five fluid endsections 102. However, more or less fluid end sections 102 may be used.Forming the fluid end 100 out of multiple fluid end sections 102 allowsa single fluid end section 102 to be replaced, if needed. In contrast,the entire housing 48 in traditional fluid ends 46 may need to bereplaced if only a portion of the housing 48 fails.

Turning to FIGS. 8 and 9 , each fluid end section 102 comprises ahorizontally positioned housing 104 having a generally cylindricalcross-sectional shape, as shown in FIG. 8 . In alternative embodiments,each fluid end section may have a generally rectangular cross-sectionalshape. In Unlike the traditional fluid end 46 shown in FIGS. 3 and 5 ,each housing 104 does not include a vertical bore intersecting ahorizontal bore to form an internal chamber. Rather, each housing 104only has a single horizontally positioned bore 106, as shown in FIG. 9 .Removing the internal chamber found in traditional fluid ends from thehousing 104 removes common stress points from the housing 104.

Eliminating the intersecting bore also reduces the cost of manufacturingthe fluid end 100 as compared to traditional fluid ends. The timerequired to manufacture the fluid end 100 is greatly reduced without theneed for machining an intersecting bore, and the fluid end 100 may bemanufactured on a lathe instead of a machining center. The fluid end 100may also be manufactured out of lower strength and less costly materialssince it does not include the high stress areas found in traditionalfluid ends. Each housing 104 may be manufactured out of high strengthalloy steel, such as carbon steel. In alternative embodiments, eachhousing 104 may be manufactured out of stainless steel.

Continuing with FIGS. 8 and 9 , each housing 104 comprises a first outersurface 108 joined to an opposed second outer surface 110 by anintermediate outer surface 112. The horizontal bore 106 extends throughthe housing 104 along a central longitudinal axis 114 and interconnectsthe opposed first and second outer surfaces 108 and 110, as shown inFIG. 9 . Each housing 104 is of single piece construction.

Since each housing 104 only has a single horizontal bore 106, fluid mustbe routed throughout the housing 104 differently from how fluid isrouted throughout a traditional fluid end housing 48. As will bedescribed in more detail herein, a fluid routing plug 116, shown inFIGS. 52-64 , is installed within each housing 104 and is configured toroute fluid throughout the housing 104.

With reference to FIGS. 6, 7, and 10-16 , each housing 104 is supportedon a single connect plate 118 in a one-to-one relationship. A pluralityof sets of stay rods 120, shown in FIG. 6 , are used to attach eachconnect plate 118 to a power end. The connect plates 118 may each beattached to the corresponding stay rods 120 prior to attaching a housing104 to a corresponding connect plate 118. Because the housings 104 areeach attached to a connect plate 118, the fluid end 100 does not includea flange like the flange 50 formed in the fluid end 46 shown in FIG. 3 .In an alternative embodiment, multiple housings may be attached to asingle, larger connect plate. In such embodiment, the stay rods arelikewise attached to the single, larger connect plate.

The stay rods 120 shown in FIG. 6 are configured for use with a modularpower end, like that shown in in U.S. Provisional Patent ApplicationSer. No. 63/053,797, authored by Thomas et al. and filed on Jul. 20,2020. A spacer 122 is installed on each stay rod 120 and is configuredto engage with a front surface of the power end. In alternativeembodiments, the stay rods may be configured like the stay rods 42 shownin FIG. 3 .

With reference to FIGS. 10-13 , each connect plate 118 has a generallyrectangular shape and has opposed first and second surfaces 124 and 126.A plurality of first passages 128 are formed around the outer peripheryof each connect plate 118. Each first passage 128 interconnects thefirst and second surfaces 124 and 126 of the connect plate 118 and isconfigured for receiving a stay rod 120. Each stay rod 120 extendsthrough a corresponding passage 128 in a one-to-one relationship.

The connect plate 118 shown in FIGS. 10-13 has four first passages 128.Likewise, four stay rods 120 are shown attached to each connect plate118 in FIG. 6 . In alternative embodiments, the connect plate may havemore than four or less than four first passages, as long as the amountof first passages corresponds with the number of stay rods being usedwith each connect plate.

Once each stay rod 120 is installed in a connect plate 118, a first end130 of each stay rod 120 projects from the first surface 124 of theconnect plate 118, as shown in FIG. 16 . A nut 132 and a washer 134 areinstalled on the projecting first end 130 of each stay rod 120 in aone-to-one relationship. The nut 132 is turned until it tightly engagesa corresponding washer 134 and the first surface 124 of the connectplate 118, thereby securing the connect plate 118 to the stay rods 120.

With reference to FIGS. 6, and 14-16 , a plurality of notches 136 areformed around the periphery of the housing 104 at its second surface110, as shown in FIGS. 14 and 15 . When the housing 104 is attached tothe connect plate 118, each notch 136 partially surrounds one of thefirst passages 128 in a one-to-one relationship. The notches 136 providespace to access the washer 134 and nut 132 during operation.

Continuing with FIGS. 10-13 , a central bore 138 is formed in eachconnect plate 118 and interconnects the first and second surfaces 124and 126. The central bore 138 is configured for receiving a stuffing box140, as described in more detail later herein. A plurality of secondpassages 142 are formed in the connect plate 118 and surround thecentral bore 138. Each second passage 142 interconnects the first andsecond surfaces 124 and 126 of the connect plate 118. The secondpassages 142 are configured to align in a one-to-one relationship with aplurality of first threaded openings 144 formed in the second surface110 of each housing 104, as shown in FIGS. 14 and 15 .

Each housing 104 is attached to the first surface 124 of a correspondingconnect plate 118 using a fastening system 146. The fastening system 146comprises a plurality of studs 148, a plurality of washers 150, and aplurality of nuts 152, as shown in FIGS. 7 and 17 . A first end 154 ofeach stud 148 is configured to mate with a corresponding one of thefirst openings 144 formed in the housing 104. The second passages 142formed in the connect plate 118 subsequently receive the plural studs148 projecting from the housing 104.

When the housing 104 and the connect plate 118 are brought together, asecond end 156 of each stud 148 projects from the second surface 126 ofthe connect plate 118. A washer 150 and a nut 152 are subsequentlyinstalled on the second end 156 of each stud 148, in a one-to-onerelationship. The nut 152 is turned until it tightly engages the washer150 and the second surface 126 of the connect plate 118, therebysecuring the housing 104 and the connect plate 118 together.

In FIGS. 10-15 , the housing 104 and connect plate 118 each have eightcorresponding first openings 144 and second passages 142. In alternativeembodiments, more than eight or less than eight corresponding openingsand second passages may be formed in the housing and connect plate. Insuch embodiments, the fastening system may comprise the same number ofstuds, washers, and nuts as there are openings and passages. In furtheralternative embodiments, the fastening system may comprise differenttypes of fasteners, such as socket-headed screws.

Continuing with FIGS. 10-15 , a pair of third passages 158 are formed inthe connect plate 118 on opposite sides of the central bore 138. Thethird passages 158 are alignable with a pair of pin holes 160 formed inthe second surface 110 of the housing 104. Each third passage 158 andeach corresponding pin hole 160 is configured to receive a dowel pin ina one-to-one relationship. The dowel pins are used to help align thehousing 104 on the connect plate 118 during assembly. A threaded hole162 may also be formed in a top surface 164 of each connect plate 118,as shown in FIGS. 10 and 11 . The threaded hole 162 is configured forreceiving a lifting eye (not shown) used to lift and support the connectplate 118 during assembly.

In alternative embodiments, the connect plate may have various shapesand sizes other than those shown in FIGS. 10-13 . For example, theconnect plate may be shaped like the various embodiments disclosed inU.S. Provisional Patent Ser. No. 63/053,797, authored by Thomas et al.and filed on Jul. 20, 2020.

Turning back to FIGS. 6 and 7 , in contrast to the traditional fluid end46, shown in FIG. 3 , the fluid end 100 is configured to receive fluidfrom two manifolds, rather than just one. The fluid end 100 comprises anupper intake manifold 166 and a lower intake manifold 168. Each manifold166 and 168 is in fluid communication with each fluid end section 102.Using two different manifolds 166 and 168 allows different types offluid to be delivered to each fluid end section 102. For example, fluidhaving a higher level of proppant may be delivered via the upper intakemanifold 166, while fluid having a zero to minimal level of proppant maybe delivered via the lower intake manifold 168.

Continuing with FIGS. 6 and 7 , the upper and lower intake manifolds 166and 168 are joined to the fluid end sections 102 via a plurality ofconduits 159. Each conduit 159 is positioned directly below thecorresponding manifold 166 and 168 and extends along a straight linebetween the fluid end section 102 and the corresponding manifold 166 and168. Thus, each conduit 159 and corresponding manifold 166 and 168 havea “T” shape.

Turning to FIGS. 7A and 7B, an alternative embodiment of an upper andlower intake manifold 161 and 163 is shown. The upper and lower intakemanifolds 161 and 163 are joined to the fluid end sections 102 via aplurality of conduits 165. The conduits 165 have an elbow shape. Theelbow shape of the conduits 165 causes the corresponding manifolds 161and 163 to be spaced farther away from a discharge manifold 167, thanthe manifolds 166 and 168. Providing more space between the intakemanifolds 161 and 163 and the discharge manifold 167 provides more spacefor maintenance to different areas of the fluid end 100, when needed.

Turning back to FIG. 9 , an upper and lower intake bore 170 and 172 areformed within the housing 104. Each bore 170 and 172 interconnects theintermediate outer surface 112 and the horizontal bore 106. The upperand lower intake bores 170 and 172 shown in FIG. 9 are collinear. Inalternative embodiments, the upper and lower intake bores may not becollinear.

With reference to FIGS. 6-9 , the upper intake bore 170 is in fluidcommunication with the upper intake manifold 166, and the lower intakebore 172 is in fluid communication with the lower intake manifold 168.In operation, fluid may be delivered into the housing 104 through boththe upper and lower intake bores 170 and 172. In alternativeembodiments, only one intake bore may be formed in the housing and onlyone intake manifold may be attached to the housing.

Continuing with FIGS. 6-9 , the fluid end 100 further comprises aplurality of discharge conduits 174. Each discharge conduit 174 isattached to one of the fluid end sections 102 in a one-to-onerelationship. A discharge manifold 176 interconnects each of thedischarge conduits 174, as shown in FIGS. 6 and 7 . In alternativeembodiments, the discharge conduits and discharge manifold may be formedas a single unit, like the discharge manifold 167, shown in FIGS. 7A and7B.

Continuing with FIG. 9 , a discharge bore 178 is formed in the housing104 and interconnects the intermediate surface 112 and the horizontalbore 106. The discharge bore 178 is positioned between the first surface108 of the housing 104 and the intake bores 170 and 172. The dischargebore 178 is in fluid communication with the discharge conduit 174. Inoperation, fluid to be pressurized enters the housing 104 through theupper and lower intake bores 170 and 172. Pressurized fluid exits thehousing 104 through the discharge bore 178.

With reference to FIG. 18 , the discharge bore 178 has an ovalcross-sectional shape, as shown by a discharge bore opening 180. Theopening 180 has a length A and a width B. The discharge bore 178 isformed within the housing 104 such that the width B extends along anaxis that is parallel to the longitudinal axis 114 of the housing 104.During operation, high fluid pressure within the discharge bore 178 maycause the walls along the length A to compress, causing the dischargebore 178 to have a more circular cross-sectional shape. Providing roomfor the walls surrounding the discharge bore 178 to compress, helpsreduce stress in the housing 104 and increase fluid flow. In alternativeembodiments, the discharge bore may have a circular cross-sectionalshape.

Continuing with FIG. 19 , a counterbore 173 is formed within the housing104 immediately above the opening 180 of the discharge bore 178. Thedischarge bore 178 opens into the counterbore 173. The counterbore 173has a circular cross-sectional shape, as shown by the opening 175 inFIG. 18 . A portion of the discharge conduit 174 is installed within thecounterbore 173 through its opening 175. A seal 182 is interposedbetween the walls of the housing 104 surrounding the discharge bore 178and an outer surface of the discharge conduit 174. The seal 182 isinstalled within a groove 184 formed in the walls of the housing 104.The seal 182 may be identical to the second seal 376, described withreference to FIGS. 65 and 70 . In alternative embodiments, the seal maybe identical to the first seal 374, described with reference to FIGS. 65and 71 .

The groove 184 is characterized by two sidewalls 185 joined to a base183. The sidewalls 185 may join the base 183 via radius corners or at a90 degree angle. No grooves are formed in the outer surface of thedischarge conduit 174 for housing a seal. In operation, the seal 182wears against the outer surface of the discharge conduit 174. If theouter surface of the discharge conduit 174 begins to erode, allowingfluid to leak around the seal 182, the discharge conduit 174 may bereplaced with a new discharge conduit 174.

The discharge bore 178 shown in FIG. 9 interconnects a top surface 113of the intermediate surface 112 of the housing 104 and the horizontalbore 106. Likewise, the discharge conduits 174 shown in FIGS. 6, 7, and9 are attached to the top surface 113 of the intermediate surface 112 ofeach housing 104. In operation, any gas trapped within the housing 104rises towards the top of the housing 104. Placing the discharge bore 178and conduit 174 at the top of the housing 104 allows the gases tonaturally escape. Additionally, any wear caused to the components by therising gas will primarily be imposed on the discharge conduit 174,rather than the housing 104. The discharge conduit 174 and correspondingdischarge piping 176 are easily replaced, if needed.

In alternative embodiments, the discharge bore may interconnect a bottomor side surface of the intermediate surface and the horizontal bore, andthe discharge conduit may be attached to the corresponding surface ofthe housing. In further alternative embodiments, the discharge bore mayinterconnect the first outer surface of the housing and the horizontalbore, and the discharge conduit may be attached to the first outersurface of the housing.

With reference to FIGS. 6, 18 and 19 , a rectangular flange 171 isformed around each discharge conduit 174. Each rectangular flange 171 isattached to the housing 104 using a plurality of threaded studs 186 andnuts 187, as shown in FIGS. 6 and 19 . A plurality of threaded openings188 are formed in the housing 104 for receiving the studs 186, as shownin FIG. 18 . The openings 188 are positioned in a rectangular patternaround the discharge bore opening 180. Such pattern helps maximize thesurface area of the intermediate surface 112 of the housing 104, helpingto reduce the size and weight of the housing 104.

With reference to FIGS. 7 and 18 , the intake manifolds 166 and 168 eachcomprise a plurality of rectangular flanges 189 joined to a plurality ofconduits 191 in a one-to-one relationship, as shown in FIG. 7 . Eachrectangular flange 189 is attached to the housing 104 using a pluralityof threaded studs 190 and nuts 193, as shown in FIG. 7 . A plurality ofthreaded openings 192 are formed in the housing 104 for receiving thestuds 190, as shown in FIG. 18 . The openings 192 are positioned in arectangular pattern around the intake bores 170 and 172 to maximizesurface area of the housing 104. In alternative embodiments, thedischarge conduits and intake manifolds may be attached to the housingusing different types of fasteners, such as socket-headed screws.

Continuing with FIG. 18 , the intermediate surface 112 of the housing104 includes a first portion 194 joined to a second portion 196 by afirst tapered portion 198. The second portion 196 is joined to a thirdportion 200 by a second tapered portion 202. The first portion 194 isjoined to the first surface 108 and the third portion 200 is joined tothe second surface no.

The second portion 196 has a smaller diameter than both the first andthird portions 194 and 200. Providing the second portion 196 with asmaller diameter helps remove unnecessary weight from the housing 104.The third portion 200 may have a slightly larger diameter than the firstportion 194. The first, second, and third portions 194, 196, and 200 aregenerally cylindrical. Thus, the housing 104 may be characterized asbeing primarily cylindrical. In alternative embodiments, the housing maybe uniform in diameter throughout its intermediate surface. In furtheralternative embodiments, the housing may have various diametersthroughout its intermediate surface other than those shown in FIG. 18 .

Continuing with FIG. 18 , a threaded hole 204 is formed in the topsurface 113 of the intermediate surface 112. The threaded hole 204 ispositioned at the center of gravity of the housing 104 when the housing104 is fully loaded with the components described herein. The threadedhole 204 is configured to receive a lifting eye (not shown) used to liftand support the housing 104 during assembly and maintenance, as shown inFIG. 9 .

With reference to FIGS. 20-29 , each fluid end section 102 furthercomprises a stuffing box 140 attached to the second outer surface no ofthe housing 104. The stuffing box 140 has a generally cylindrical shapeand comprises a first outer surface 206 joined to an opposed secondouter surface 208 by an intermediate outer surface 210. The intermediatesurface 210 includes a cylindrical first portion 212 joined directly toa cylindrical second portion 214. The first portion 212 is positionedadjacent the first surface 206 and has a reduced diameter from that ofthe second portion 214. A threaded hole 215 is formed in a top surfaceof the second portion 214. The threaded hole 215 is configured toreceive a lifting eye (not shown) used to lift and support the stuffingbox 140 during assembly and maintenance.

A central passage 216 interconnects the stuffing box's first and secondouter surfaces 206 and 208. The walls surrounding the central passage216 include a first section 218 joined to a second section 220 by atapered shoulder 222, as shown in FIGS. 25, 26, and 29 . The secondsection 220 has a larger diameter than that of the first section 218. Asdescribed in more detail herein, the second section 220 and the taperedshoulder 222 are configured for receiving a plunger packing 224, asshown in FIGS. 20 and 21 .

Continuing with FIGS. 23-29 , a plurality of passages 226 are formedaround the periphery of the second portion 214 of the stuffing box 140.Each passage 226 interconnects the second surface 208 of the stuffingbox 140 and a base 228 of the second portion 214. The passages 226 areformed parallel to the central passage 216.

Turning back to FIGS. 14 and 15 , a plurality of second threadedopenings 230 are formed in the second surface no of the housing 104. Theopenings 230 surround the opening of the horizontal bore 106. The secondopenings 230 are surrounded by the first openings 144 used with theconnect plate 118.

Continuing with FIGS. 20 and 21 , the walls surrounding the horizontalbore 106 adjacent the second surface 110 of the housing 104 are sized toreceive the first portion 212 of the stuffing box 140. The first portion212 is installed within the horizontal bore 106 such that the base 228of the second portion 214 abuts the second surface 110 of the housing104. A portion of the second portion 214 is disposed within the centralbore 138 formed in the connect plate 118. The stuffing box 140 isaligned on the housing 104 such that the passages 226 align with thesecond openings 230 in a one-to-one relationship.

With reference to FIGS. 20, 21, and 30-37 , the stuffing box 140 isattached to the housing 104 using a retainer 232 and a fastening system234. The retainer 232 has a generally cylindrical shape and comprisesopposed first and second outer surfaces 236 and 238 joined by anintermediate surface 240. A central passage 242 interconnects the firstand second outer surfaces 236 and 238. At least a portion of the centralpassage 242 has internal threads 244. A plurality of side passages 246are formed in the retainer 232. Each passage 246 interconnects thecentral passage 242 and the intermediate surface 240. The passages 246provide a pathway for lubricating oil to be introduced to the horizontalbore 106 during operation. The oil lubricates the moving parts withinthe housing 104 during operation.

Continuing with FIGS. 30-37 , a plurality of passages 248 are formed inthe retainer 232 and surround the central passage 242. Each passage 248interconnects the first and second outer surfaces 236 and 238. The firstsurface 236 of the retainer 232 is positioned on the second surface 208of the stuffing box 140 such that the passages 248 align with thepassages 226 formed in the stuffing box 140, in a one-to-onerelationship.

A pair of dowel pin holes 241 are formed in the second surface 208 ofthe stuffing box 140, as shown in FIGS. 27 and 28 . A corresponding pairof dowel pin holes 243 are formed in the first surface 236 of theretainer 232, as shown in FIGS. 31 and 32 . The holes 241 and 243 areconfigured for receiving a dowel pin. The dowel pin aligns the retainer232 on the stuffing box 140 during assembly.

Turning back to FIGS. 20 and 21 , the fastening system 234 secures boththe retainer 232 and the stuffing box 140 to the housing 104. Thefastening system 234 comprises a plurality of studs 250, nuts 252, andwashers 254. A first end 256 of each stud 250 mates with one of thesecond openings 230 in the housing 104 in a one-to-one relationship. Thepassages 226 in the stuffing box 140 and the passages 248 in theretainer 232 subsequently receive the plural studs 250 projecting fromthe housing 104.

A second end 258 of each stud 250 projects from the second surface 238of the retainer 232. The projecting second end 258 of each stud 250receives a washer 254 and a nut 252. The nut 252 is turned until ittightly engages the washer 254 and the second surface 238 of theretainer 232, thereby securing the retainer 232 and the stuffing box 140together. The retainer 232, in turn, holds the stuffing box 140 againstthe housing 104. The stuffing box 140 and the retainer 232 may beattached to and removed from the housing 104 without removing theconnect plate 118.

When the first portion 212 of the stuffing box 140 is installed withinthe housing 104, a seal 260 is interposed between the walls of thehousing 104 and outer surface of the first portion 212. The seal 260 isinstalled within a groove 262 formed in the walls of the housing 104.The seal 260 may be identical to the first seal 374, described withreference to FIGS. 65 and 71 . In alternative embodiments, the seal maybe identical to the second seal 376, described with reference to FIGS.65 and 70 .

The groove 262 is characterized by two sidewalls 264 joined by a base266, as shown in FIG. 21 . The sidewalls 264 may join the base 266 viaradius corners or at a 90 degree angle. No grooves are formed in thefirst portion 212 of the stuffing box 140 for housing a seal. The seal260 wears against the outer surface of the first portion 212 duringoperation. If the outer surface of the first portion 212 begins toerode, allowing fluid to leak around the seal 260, the stuffing box 140may be replaced with a new stuffing box 140.

When the stuffing box 140 is attached to the housing 104 using thefastening system 234, a first end 256 of the studs 250 may be installedwithin the housing 104 such that they extend past the seal 260, as shownin FIG. 20 . An edge of the studs 250 may not be purposely aligned withan edge of the seal 260 in order to prevent areas of high stress frombeing aligned with one another in the housing 104, potentially causing astress riser.

Continuing with FIGS. 20, 21, and 38-42 , a plunger packing 224 isinstalled within the central passage 216 of the stuffing box 140. Theplunger packing 224 engages the tapered shoulder 222 and is positionedwithin the second section 220 of the central passage 216, as shown inFIGS. 20 and 21 . A portion of the plunger packing 224 may extend intothe central passage 242 of the retainer 232. The plunger packing 224 hasa central passage 268 that aligns with the central passages 216 and 242when the plunger packing 224 is installed within the stuffing box 140and the retainer 232. In alternative embodiments, the plunger packingmay be sized to not extend into the retainer.

The plunger packing 224 comprises a pair of outer ring seals 270 and 271and at least one inner ring seal 272. The outer ring seals 270 and 271may be made of metal while the inner ring seals 272 may be made of anelastomer material. The outer ring 270 has a tapered outer surface 274that is sized to engage the tapered shoulder 222 formed in the centralpassage 216. The tapered engagement helps reduce stress in the stuffingbox 140 during operation. In alternative embodiments, the wallssurrounding the central passage of the stuffing box may include anannular shoulder rather than a tapered shoulder. In such embodiment, theplunger packing may have a flat outer ring configured to mate with theannular shoulder. A plurality of holes 275 are formed in the outer ring271. The holes 275 are in fluid communication with the side passages 246formed in the retainer 232 in order to deliver lubricating oil to thehousing 104.

With reference to FIGS. 20, 21, and 43-46 , a packing nut 276 isinstalled within the retainer 232 and engages the plunger packing 224.The packing nut 276 comprises a first surface 278 joined to an opposedsecond surface 280 by an intermediate surface 282. A central passage 284extends through the packing nut 276 and interconnects the opposed firstand second surfaces 278 and 280. A plurality of side holes 286 areformed in the packing nut 276 and interconnect the central passage 284and the intermediate surface 282. The holes 286 are configured forengaging a tool used to grip the packing nut 276.

Continuing with FIGS. 43-46 , external threads 288 are formed in aportion of the intermediate surface 282 of the packing nut 276. Theexternal threads 288 are configured to mate with the internal threads244 formed within the retainer 232, as shown in FIGS. 20 and 21 . Themating threads 288 and 244 are buttress threads. The buttress threadsare configured to handle a large amount of load using a low amount ofthreads. Using a low amount of threads allows the packing nut 276 to bequickly removed or installed within the retainer 232. In alternativeembodiments, the packing nut and retainer may mate using traditionalthreads.

When the packing nut 276 is installed within the retainers 232, thefirst surface 278 of the packing nut 276 engages an outer ring seal 270of the plunger packing 224. Such engagement compresses the plungerpacking 224, creating a tight seal. After the packing nut 276 has beeninstalled within a retainer 232, the central passage 284 within thepacking nut 276 is aligned with the central passage 268 in the plungerpacking 224.

Continuing with FIGS. 20 and 21 , when the stuffing box 140 and theretainer 232 are attached to the housing 104, the central passages 216and 242 align with the horizontal bore 106. Likewise, the centralpassages 268 and 284 in the installed plunger packing 224 and packingnut 276 align with the horizontal bore 106. Thus, the central passages216, 242, 268, and 284 may be considered an extension of the horizontalbore 106. A plunger 290 is disposed with the installed plunger packing224 and the packing nut 276, as shown in FIG. 20 . In operation, theplunger 290 reciprocates within the horizontal bore 106 in order topressurize fluid contained with the housing 104.

With reference to FIGS. 20, 21, and 47-49 , the horizontal bore 106 issealed at the first surface 108 of the housing 104 by a retainer 300.The retainer 300 has a first surface 302 joined to an opposed secondsurface 304 by an outer intermediate surface 306. A cutout 308 is formedin the second surface 304 for receiving a portion of a discharge valveguide 298. A central passage 310 is formed in the retainer 300 andinterconnects the first surface 302 and the cutout 308. The wallssurrounding the central passage 310 have a polygonal shape. Thepolygonal shape is configured to mate with a tool used to grip theretainer 300.

The intermediate surface 306 of the retainer 300 has external threads312 that mate within internal threads 314 formed in the wallssurrounding the horizontal bore 106 adjacent the first surface 108 ofthe housing 104, as shown in FIGS. 20 and 21 . The mating threads 312and 314 are buttress threads. The buttress threads are configured tohandle a large amount of load using a low amount of threads. Using a lowamount of threads allows the retainer 300 to be quickly removed from orinstalled within the housing 104. In alternative embodiments, theretainer may mate with the housing using traditional threads. In furtheralternative embodiments, the retainer may be secured to the housingusing a fastening system, as shown for example in FIG. 132 .

Turning now to FIGS. 50 and 51 , the fluid routing plug 116 is installedwithin a medial section of the horizontal bore 106. The fluid routingplug 116 is configured to engage with a suction valve 292 on one sideand a discharge valve 294 on the opposite side. In operation, thesuction and discharge valves 292 and 294 move axially along an axis thatis parallel to or aligned within the central longitudinal axis 114 ofthe housing 104, shown in FIG. 9 , as the valves 292 and 294 move atalternating times between an open and closed position. In the closedposition, the valves 292 and 294 are pressed against the fluid routingplug 116, preventing fluid from exiting the plug 116. In the openposition, the valves 292 and 294 are spaced from the fluid routing plug116, allowing fluid to flow from the plug 116.

As will be described in more detail herein, axial movement of thesuction valve 292 is limited by a suction valve guide 296 installedwithin the housing 104. Likewise, axial movement of the discharge valve294 is limited by the discharge valve guide 298 installed within thehousing 104.

Turning now to FIGS. 52-64 , the fluid routing plug 116 comprises a body316 having opposed first and second outer surfaces 318 and 320 joined byan intermediate outer surface 322. The first outer surface 318 may alsobe referred to as the suction side of the fluid routing plug 116. Thesecond outer surface 320 may also be referred to as the discharge sideof the fluid routing plug 116. A central longitudinal axis 324 extendsthrough the body 316 and both surfaces 318 and 320, as shown in FIG. 55.

A plurality of first fluid passages 326 are formed within the body 316and interconnect the intermediate surface 322 and the first surface 318.The first fluid passages 326 interconnect the intermediate surface 322and the first surface 318 by way of an axial-blind bore 328, as shown inFIG. 55 . The blind bore 328 extends along the central longitudinal axis324 of the body 316. The first fluid passages 326 each open into theblind bore 328 via a plurality of openings 330. A longitudinal axis 332of each first fluid passage 326 intersects the central longitudinal axis324 of the body 316, as shown in FIG. 58 .

The fluid routing plug 116 shown in FIGS. 52-64 has four first fluidpassages 326 formed in its body 316. The first fluid passages 326 areequally spaced around the body 316. In alternative embodiments, morethan four or less than four first fluid passages may be formed in thebody and may be equally or unequally spaced apart from one another.

Continuing with FIG. 55 , the first fluid passages 326 extend betweenthe intermediate surface 322 and the blind bore 328 at a non-right anglerelative to the central longitudinal axis 324—the acute angle facing thesecond surface 320 of the body 316. Forming the first fluid passages 326at such angle reduces the amount of stress in the fluid routing plug 116as fluid flows through the first fluid passages 326. Forming the firstfluid passages 326 at such an angle also helps direct fluid flow towardsthe blind bore 328 and the first surface 318.

With reference to FIGS. 57 and 59 , the first fluid passages 326 have anoval cross-sectional shape, as shown by an opening 334 of each firstfluid passage 326 on the intermediate surface 322. Each opening 334 hasa length A and a width B, as shown in FIG. 59 . The first fluid passages326 are formed in the body 316 such that the length A extends along anaxis that is parallel to the central longitudinal axis 324 of the body316. Orienting the first fluid passages 326 as such helps reduce theamount of stress in the body 316 as fluid flows through the first fluidpassages 326 and helps maximize the rate of fluid flow through thepassages 326. In alternative embodiments, the first fluid passages mayhave a different cross-sectional shape, such as a circular or oblongshape. In further alternative embodiments, the first fluid passages maybe shaped like the first fluid passages 910, shown in FIGS. 121 and 124.

With reference to FIGS. 60-63 , the fluid routing plug 116 furthercomprises a plurality of second fluid passages 336 formed in the body316. The second fluid passages 336 each have a circular cross-sectionalshape and interconnect the first and second surfaces 318 and 320 of thebody 316. In alternative embodiments, the second fluid passages may havea different cross-sectional shape, such as an oval or oblong shape.

Unlike the first fluid passages 326, the second fluid passages 336 donot intersect an axially blind bore. Rather, each second fluid passage336 extends between the first and second surface 318 and 320 along astraight-line path. The second fluid passages 336 and the first fluidpassages 326 do not intersect and are positioned offset from oneanother, as shown in FIG. 58 . Positioning the first and second passages326 and 336 offset from one another helps minimize the stress in thefluid routing plug 116 during operation. The fluid routing plug 116shown in FIGS. 52-64 has twelve second fluid passages 336 formed in itsbody 316. In alternative embodiments, more or less than twelve secondfluid passages may be formed in the body.

Each second fluid passage 336 extends between the first and secondsurfaces 318 and 320 along a different axis, as shown in FIGS. 60-63 .Each axis is positioned at a non-zero angle relative to the centrallongitudinal axis 324 of the body 316. Forming each second passage 336along a different axis helps alleviate stress in the fluid routing plug116 during operation and helps maximize the rate of fluid flow throughthe second passages 336.

Turning back to FIGS. 53, 55, and 56 , the first surface 318 of the body316 includes an outer rim 338 joined to a tapered wall 340. The outerrim 338 may taper slightly between the intermediate surface 322 and thetapered wall 340, as shown in FIG. 55 . Such taper provides more surfacearea for the tapered wall 340 without increasing the length of theintermediate surface 322. The tapered wall 340 extends between anentrance 342 of the blind bore 328 and the outer rim 338 at an angle ofat least 30 degrees relative to the central longitudinal axis 324 of thebody 316. Preferably, the tapered wall 340 is formed at an angle of 45degrees relative to the central longitudinal axis 324 of the body 316,as is shown in FIG. 55 . As will be described in more detail laterherein, the tapered wall 340 forms a cavity 344 within the first surface318 of the body 316 that is sized to receive a sealing element 346 ofthe suction valve 292, as shown in FIGS. 72-76 .

Continuing with FIGS. 53 and 56 , the second fluid passages 336 open onthe outer rim 338 of the first surface 318, as shown by the openings348. The second fluid passages 336 are formed within the body 316 suchthat the openings 348 are positioned in groups 350 around the outer rim338. The first surface 318 shown in FIG. 59 comprises four groups 350 ofopenings 348, each group 350 comprising three openings 348. Adjacentopenings 348 within each group 350 are equally spaced. The spacingbetween the nearest openings 348 of adjacent groups 350 exceeds thespacing between adjacent openings 348 within a single group 350. Spacingthe openings 348 in groups 350 helps achieve the ideal velocity of fluidflow through the fluid routing plug 116 and allows the second fluidpassages 336 to be offset from the first fluid passages 326, as shown inFIG. 58 . In alternative embodiments, the openings may be spaced indifferently sized groups or different patterns than that shown in FIG.56 .

With reference to FIGS. 52, 54, and 55 , the second surface 320 of thebody 316 comprises an outer rim 352 joined to a central base 354 by atapered wall 356. The tapered wall 356 extends between the central base354 and the outer rim 352 at an angle of at least 30 degrees relative tothe central longitudinal axis 324 of the body 316. Preferably, thetapered wall 356 is formed at an angle of 45 degrees relative to thecentral longitudinal axis 324 of the body 316, as is shown in FIG. 55 .As will be described in more detail later herein, the tapered wall 356forms a cavity 358 within the second surface 320 of the body 316 that issized to receive a sealing element 360 of the discharge valve 294, asshown in FIGS. 85-89 .

Continuing with FIGS. 52, 54, and 55 , a blind bore 362 is formed in thecenter of the central base 354. The walls surrounding the blind bore 362may be configured to mate with a tool used to grip the fluid routingplug 116. For example, the walls surrounding the blind bore 362 may bethreaded. The second fluid passages 336 open on the central base 354 ofthe second surface 320, as shown by the openings 364 in FIGS. 52 and 54. The 10 second fluid passages 336 are formed within the body 316 suchthat the openings 364 surround the opening of the blind bore 362. Theopenings 364 shown in FIG. 54 are all equally spaced from one anotheraround the opening of the blind bore 362. In alternative embodiments,the openings of the second fluid passages on the central base may notall be equally spaced apart from one another.

Continuing with FIG. 55 , in order to provide space for the openings 364on the second surface 320, the tapered wall 356 has a greater diameterthan the tapered wall 340 formed in the first surface 318. Thus, as willbe described in more detail herein, the sealing element 360 of thedischarge valve 294 is larger in size than the sealing element 346 ofthe suction valve 292, as shown in FIGS. 72-76 and 85-89 .

Turning back to FIGS. 50 and 51 , the fluid routing plug 116 isinstalled within the horizontal bore 106 such that the first fluidpassages 326 are in fluid communication with the upper and lower intakebores 170 and 172. The upper and lower intake bores 170 and 172 directfluid into the first fluid passages 326 of the fluid routing plug 116.The first fluid passages 326 direct the fluid into the blind bore 328and towards the first surface 318 of the fluid routing plug 116.

When the plunger 290 is retracted from the housing 104, the fluidflowing through the first fluid passages 326 forces the suction valve292 to move axially away from the first surface 318. Such position isconsidered an open position of the suction valve 292. When the suctionvalve 292 is spaced from the first surface 318, fluid flows out of theblind bore 328, through the gap between the first surface 318 and thesuction valve 292. From there, the fluid flows around the suction valve292 and the suction valve guide 296 and into the horizontal bore 106. Afirst fluid flow path for the fluid to be pressurized is shown by thearrows 366 in FIG. 50 .

With reference to FIG. 51 , as the plunger 290 extends into thehorizontal bore 106, the plunger 290 forces fluid in the horizontal bore106 back towards the fluid routing plug 116. Pressurized fluid forcedback towards the fluid routing plug 116 by the plunger 290 forces thesuction valve 292 to seal against the first surface 318, sealing theentrance 342 of the blind bore 328. Such position is considered a closedposition of the suction valve 292. Once the entrance 342 of the blindbore 328 is sealed, the only place for fluid to flow is through theopenings 348 of the second fluid passages 336 on the outer rim 338 ofthe first surface 318.

Fluid flows into the openings 348 on the first surface 318 and throughthe second passages 336 towards the second surface 320 of the fluidrouting plug 116. The pressurized fluid at the second surface 320 forcesthe discharge valve 294 to move axially away from the second surface320, unsealing the openings 364 of the second fluid passages 336. Suchposition is considered an open position of the discharge valve 294.Pressurized fluid is then allowed to flow around the discharge valve 294and into the discharge bore 178. A second fluid flow path for thepressurized fluid is shown by the arrows 368 in FIG. 51 .

When the plunger 290 retracts from the housing 104, the fluid pressureon the back side of the discharge valve 294 is greater than the fluidpressure within the fluid routing plug 116. Such pressure differentialcauses the discharge valve 294 to seal against the second surface 320,sealing the openings 364 of the second fluid passages 336. Such positionis considered the closed position of the discharge valve 294.

Turning to FIG. 64 , the intermediate surface 322 of the fluid routingplug 116 varies in diameter throughout its length and generallydecreases in size from its second surface 320 to its first surface 318.The intermediate surface 322 comprises a first sealing surface 370positioned adjacent the first surface 318 and a second sealing surface372 positioned adjacent the second surface 320. The first and secondsealing surfaces 370 and 372 each extend around the entire intermediatesurface 322 in an endless manner and surround the longitudinal axis 324of the body 316. The first and second sealing surfaces 370 and 372 shownin FIG. 64 are annular. In alternative embodiments, the first and secondsealing surfaces may have non-annular shape, such as an oval shape.

The first sealing surface 370 has a smaller diameter than the secondsealing surface 372. As will be described in more detail herein, thefirst and second sealing surfaces 370 and 372 are configured to engage afirst and second seal 374 and 376 installed within the housing 104, asshown in FIGS. 70 and 71 .

Continuing with FIG. 64 , the intermediate surface 322 of the fluidrouting plug 116 further comprises a first bevel 378 positioned betweenthe opening 334 of the first fluid passages 326 and the first sealingsurface 370. The first bevel 378 extends around the entire intermediatesurface 322 in an endless manner and surrounds the longitudinal axis 324of the body 316. The first bevel 378 shown in FIG. 64 is annular. Inalternative embodiments, the first bevel may have a non-annular shape,such as an oval shape.

A maximum diameter of the first bevel 378 is greater than the diameterof the first sealing surface 370. The maximum diameter of the firstbevel 378 is positioned adjacent the openings 334 of the first fluidpassages 326 and a minimum diameter of the first bevel 378 is positionedadjacent the first sealing surface 370. As will be described in moredetail later herein, the first bevel 378 corresponds with a firstbeveled surface 380 formed in the housing 104, as shown in FIGS. 65 and69 .

The intermediate surface 322 also comprises a second bevel 382positioned between the second sealing surface 372 and the openings 334of the first fluid passages 326. The second bevel 382 extends around theentire intermediate surface 322 in an endless manner and surrounds thelongitudinal axis 324 of the body 316. The second bevel 382 shown inFIG. 64 is annular. In alternative embodiments, the first bevel may havenon-annular shape, such as an oval shape.

A maximum diameter of the second bevel 382 is positioned adjacent thesecond sealing surface 372 and a minimum diameter of the second bevel382 is positioned adjacent the openings 334 of the first fluid passages326. The second sealing surface 372 and the maximum diameter of thesecond bevel 382 both have a greater diameter than the maximum diameterof the first bevel 378 and the diameter of the first sealing surface370.

As will be described in more detail later herein, the second bevel 382corresponds with a second beveled surface 384 formed in the housing 104,as shown in FIGS. 65 and 68 . A small transition bevel 386 may extendbetween the second sealing surface 372 and the second bevel 382.However, the transition bevel 386 does not engage the second beveledsurface 384, as shown in FIG. 68 . The transition bevel 386 helps reducefriction between the fluid routing plug 116 and the housing 104 duringinstallation.

As described above, the first and second bevels 378 and 382 arepositioned between the first and second sealing surfaces 370 and 372.The first and second bevels 378 and 382 help alleviate stress in thefluid routing plug 116 during operation. In alternative embodiments, theintermediate surface may only include a single bevel positioned betweenthe first and second sealing surfaces.

Continuing with FIG. 64 , the various diameters of the intermediatesurface 322 are shown in more detail. The first sealing surface 370 hasa diameter D₁. The maximum diameter of the first bevel 378 has adiameter D₂. The maximum diameter of the second bevel 382 has a diameterD₃, and the second sealing surface 372 has a diameter D₄. As describedabove in detail, D₄ is greater than D₃, D₃ is greater than D₂, and D₂ isgreater than D₁.

With reference to FIG. 65 , in addition to being shaped to alleviatestress, the intermediate surface 322 is shaped to allow for easyinstallation of the fluid routing plug 116 within the horizontal bore106. The fluid routing plug 116 is installed into the horizontal bore106 at the first outer surface 108 of the housing 104. The fluid routingplug 116 is installed with the first surface 318 entering the horizontalbore 106 before the second surface 320. The fluid routing plug 116 ispushed into the horizontal bore 106 until the first sealing surface 370engages the first seal 374 and the second sealing surface 372 engagesthe second seal 376.

The first sealing surface 370 and first bevel 378 have smaller diametersthan the second seal 376 and the second beveled surface 384. Thus,clearance exists between these features as the fluid routing plug 116 isinstalled into the horizontal bore 106. Providing such clearance duringinstallation avoids unnecessary wear to both the housing 104 and fluidrouting plug 116 during installation.

With reference to FIGS. 65 and 67 , once the fluid routing plug 116 isinstalled within the housing 104, an annular chamber 388 is formedbetween the walls of the housing 104 and the intermediate surface 322.The intake bores 170 and 172 open into the chamber 388. Only a couple ofthe openings 334 of the first fluid passages 326 may align with theintake bores 170 and 172. Alternatively, the fluid routing plug 116 maybe installed within the housing 104 such that none of the openings 334directly align with the intake bores 170 and 172. The chamber 388provides a pathway for fluid from the intake bores 170 and 172 to flowaround the fluid routing plug 116 and into the openings 334 of the firstfluid passages 326. The chamber 388 also provides space for proppant orother debris to collect during operation.

Continuing with FIG. 67 , the walls of the housing 104 surrounding thehorizontal bore 106 immediately adjacent the intake bores 170 and 172are beveled, as shown by bevels 390 and 392. The bevels 390 and 392 helpreduce stress in the housing 104 during operation and increase the sizeof the annular chamber 388. In alternative embodiments, the bevels 390and 392 may be larger than those shown in FIG. 67 in order to increasethe size of the chamber 388, as shown for example in FIG. 100F.Similarly, the walls of the housing 104 surrounding the horizontal bore106 immediately adjacent the discharge bore 178 are also beveled, asshown by the bevel 394 in FIG. 66 . The bevel 394 reduces stress in thehousing 104 during operation and helps direct fluid into the dischargebore 178.

Continuing with FIGS. 65 and 68 , the second bevel 382 and the secondbeveled surface 384 are shown in more detail. The second beveled surface382 is positioned between the second seal 376 and the intake bores 170and 172. The second beveled surface 384 has an annular shape andsurrounds the horizontal bore 106 in an endless manner. In alternativeembodiments, the second beveled surface may have a shape that conformsto the shape of the second bevel formed in the fluid routing plug.

When the fluid routing plug 116 is installed within the horizontal bore106, the second bevel 382 seats against the second beveled surface 384,as shown in FIG. 68 . The bevels 382 and 384 meet at a non-right angle.Such angle reduces stress in the fluid routing plug 116 and the housing104 during operation. The bevels 382 and 384 remain engaged during theforward and backwards stroke of the plunger 290.

Turning to FIGS. 65 and 69 , the first bevel 378 and the first beveledsurface 380 are shown in more detail. The first beveled surface 380 ispositioned between the intake bores 170 and 172 and the first seal 374.The first beveled surface 380 has an annular shape and surrounds thehorizontal bore 106 in an endless manner. In alternative embodiments,the first beveled surface may have a shape that conforms to the shape ofthe first bevel formed in the fluid routing plug.

In contrast to the second bevel 382, the first bevel 378 is sized to bespaced from the first beveled surface 380 when the fluid routing plug116 is initially installed within the housing 104, as shown by a gap398. The gap 398 provides space for the fluid routing plug 116 to expandduring operation.

As the plunger 290 retracts backwards away from the housing 104, asignificant amount of load is applied to the second bevel 382. Theapplied load causes the fluid routing plug 116 to slightly compress,forcing the intermediate surface 322 at the first bevel 378 to expandoutwards. As the first bevel 378 expands, it eventually engages with thefirst beveled surface 380. Upon engaging the first beveled surface 380,the load being applied to the second bevel 382 is shared with the firstbevel 378, thereby decreasing the load applied to the second bevel 382.Without the gap 398, the fluid routing plug 116 would not have room toexpand, potentially causing damage to the fluid routing plug 116 and thehousing 104 over time.

As the plunger 290 extends forward into the housing 104, the first bevel378 will return to its un-expanded state, re-creating the gap 398. Thegap 398 will repeatedly be created and closed during operation as theplunger 290 reciprocates. In addition to providing space for the fluidrouting plug 116 to expand, the gap 398 also provides a gas and fluidrelief area during the forward stroke of the plunger 290.

Continuing with FIGS. 68 and 69 , because the second bevel 382 carriesthe majority of the load experienced by the fluid routing plug 116during operation, the second bevel 382 is longer than the first bevel378. In alternative embodiments, the first bevel may be longer than thatshown in FIG. 69 or be equal in length to the second bevel. In suchembodiments, the first beveled surface formed in the housing maycorrespond with the chosen size of the first bevel. In furtheralternative embodiments, the first bevel may be sized to mate with thefirst beveled surface when the fluid routing plug is first installedwithin the housing.

With reference to FIGS. 65, 70, and 71 , in order to prevent fluid fromleaking around the fluid routing plug 116 during operation, the firstand second seals 374 and 376 are positioned between the sealing surfaces370 and 372 and the walls of the housing 104 surrounding the horizontalbore 106.

The first seal 374 is positioned within a first annular groove 400formed in housing 104 and surrounding the horizontal bore 106 in anendless manner. The first groove 400 is positioned between the intakebores 170 and 172 and the second outer surface 110 of the housing 104,as shown in FIG. 65 . The first groove 400 is characterized by twosidewalls 402 joined by a base 404, as shown in FIG. 71 . The sidewalls402 may join the base 404 via radius corners or at a 90 degree angle. Inalternative embodiments, the first groove may have a non-concentricshape that corresponds with the shape of the first sealing surface.

The second seal 376 is positioned within a second annular groove 406formed in the housing 104 and surrounding the horizontal bore 106 in anendless manner. The second groove 406 is positioned between thedischarge bore 178 and the intake bores 170 and 172, as shown in FIG. 65. The second groove 406 is characterized by two sidewalls 408 joined bya base 410. The sidewalls 408 may join the base 410 via radius cornersor at a 90 degree angle. In alternative embodiments, the second groovemay have a non-concentric shape that corresponds with the shape of thesecond sealing surface.

The second groove 406 has a larger diameter than that of the firstgroove 400 due to the diameter of the horizontal bore 106 at eachgroove, as shown in FIG. 65 . Likewise, the second seal 376 has a largerdiameter than that of the first seal 374. Because the first and secondgrooves 400 and 406 are formed in the housing 104, no grooves are formedin the intermediate surface 322 of the fluid routing plug 116 forreceiving a seal.

When the fluid routing plug 116 is installed within the horizontal bore106, the first and second seal 374 and 376 tightly engage thecorresponding first and second sealing surfaces 370 and 372, as shown inFIGS. 70 and 71 . During operation, the first and second seals 374 and376 wear against the first and second sealing surfaces 370 and 372. Ifthe first or second sealing surface 370 or 372 begins to erode, allowingfluid to leak around the fluid routing plug 116, the plug 116 may beremoved and replaced with a new plug 116. The first or second seal 374or 376 may also be replaced with a new seal, if needed.

The first groove 400 shown in FIG. 71 is wider than the second groove406 shown in FIG. 70 . As described below, each groove 400 and 406 issized to correspond with the size of the seal installed within thegroove. In alternative embodiments, the first and second grooves may bewider or narrower than those shown in the figures in order toaccommodate the size of the seal installed within the groove.

As discussed above, the fluid routing plug 116 may repeatedly stretchand contract in response to the changing fluid pressure. For example,when the plunger 290 is retracted out of the housing 104, the fluidpressure at the first surface 318 is equal or approximately equal to thepressure of fluid delivered to the housing 104 from the intake manifolds166 and 168. Such fluid pressure may be around 100-200 psi, for example.When the plunger 290 extends into the housing 104, the fluid at thefirst surface 318 may be pressurized to around 10,000 psi, for example.

The first seal 374, being positioned adjacent the first surface 318 ofthe fluid routing plug 116 experiences the constant change in fluidpressure. In contrast, the second seal 376, being positioned adjacentthe second surface 320, experiences more static fluid pressure. Thefluid pressure at the second surface 320 of the fluid routing plug 116may remain at or close to 10,000 psi, for example.

Continuing with FIGS. 70 and 71 , because the first seal 374 experiencesmore pressure fluctuations during operation than the second seal 376,the first seal 374 may be more robust than the second seal 376. Forexample, the first seal 374 is larger than the second seal 376 and has agenerally square cross-sectional shape, while the second seal 376 has acircular cross-sectional shape. The first seal 374 may also have ahigher durometer value than the second seal 376. As described below,both seals 374 and 376 are bi-directional seals. In alternativeembodiments, the second seal may be of the same construction as thefirst seal.

Continuing with FIG. 71 , the first seal 374 is shown engaged with bothside walls 402 of the first groove 400. In operation, as the plunger 290extends into the housing 104, pressurized fluid pushes against the rightside of the first seal 374, helping to activate the first seal 374 andcreate a tight seal between the first seal 374 and the first sealingsurface 370. As the plunger 290 retracts from the housing 104 and thefluid pressure drops, the fluid pressure is greater on the left side ofthe first seal 374. Thus, the fluid pressure may push against the leftside of the first seal 374, helping to activate the first seal 374.Therefore, in operation, the first seal 374 may move slightly betweenits left and right side.

Continuing with FIG. 70 , the second seal 376 is shown engaged with bothside walls 408 of the second groove 406. In operation, pressurized fluidwithin the housing 104 helps to activate the second seal 376, therebycreating a tight seal between the second seal 376 and the second sealingsurface 372. Because the second seal 376 experiences primarily staticfluid pressure, the second seal 376 may not move within the secondgroove 406, as much as the first seal 374 moves within the first groove400.

Continuing with FIGS. 70 and 71 , the first seal 374 also takes upapproximately 97% of the open volume within the first groove 400.Likewise the second seal 376 takes up almost 97% of the open volumewithin the second groove 406. Normally, seals are configured to take uparound 70% of the open volume within the groove the seal is installedwithin. The remaining open volume provides space for the seal to expandand move. However, in operation, fluid and proppants can fill the openvolume and wear against the groove, eventually causing the walls of thegroove to erode. If the walls of the groove are damaged, the housing 104may need to be replaced.

By sizing the grooves 400 and 406 so that the seals 374 and 376 take upalmost all of the open volume within the corresponding grooves 400 and406, there is less room for fluid or proppants to fill any open spacewithin the grooves. Specifically, fluid and proppants are prevented fromentering any open volume on the back side of the seals 374 and 376,thereby protecting the first and second grooves 400 and 406 fromerosion. In alternative embodiments, the first seal may take less volumeof the first groove than is shown in FIG. 70 . Likewise, in alternativeembodiments, the second seal may take up less volume of the secondgroove than is shown in FIG. 71 . The other grooves formed in thehousing and described herein may also be configured so that thecorresponding seals take up approximately 97% of the open volume withinthe groove.

Continuing with FIG. 71 , the first sealing surface 370 may extend up toimmediately adjacent the first surface 318 of the body 316. A firstportion 412 of the intermediate surface 322 between the first bevel 378and the first sealing surface 370 faces the housing 104 walls. A verysmall gap exists between the first portion 412 and the housing 104. Thegap may be as small as 0.001 inches in width. Such gap providesclearance to reduce friction between the fluid routing plug 116 and thehousing 104 during installation and operation. Such gap also providesspace for excess proppant to collect during operation.

Continuing with FIG. 70 , a second portion 416 of the intermediatesurface 322 between the second sealing surface 372 and the secondsurface 320 may face the walls of the housing 104. A third portion 418of the intermediate surface 322 between the second sealing surface 372and the transition bevel 386 may also face the walls of the housing 104.Like the first portion 412, a very small gap exists between the secondand third portions 416 and 418 and the housing 104. The gaps may be assmall as 0.001 inches in width. Such gaps provide clearance to reducefriction between the fluid routing plug 116 and the housing 104 duringinstallation and operation. Such gaps also provide space for excessproppant to collect during operation.

Turning back to FIG. 65 , as discussed above, the walls of the housing104 surrounding the horizontal bore 106 are sized to allow for easyinstallation of the fluid routing plug 116. The second groove 406 has adiameter Di. A maximum diameter of the second beveled surface 384 has adiameter D₂. A maximum diameter of the first beveled surface 380 has adiameter D₃, and the first groove 400 has a diameter D₄. The diameter D₄is greater than the diameter D₃. The diameter D₃ is greater than thediameter D₂, and the diameter D₂ is greater than the diameter Di.

With reference to FIGS. 72-76 and 85-89 , the suction and dischargevalves 292 and 294 are generally identical, with the exception that thedischarge valve 294 may be larger in size than the suction valve 292. Asdiscussed above, the suction and discharge valves 292 and 294 each havea sealing element 346 and 360. The sealing elements 346 and 360 eachinclude a sealing surface 420 and 422 that tapers at an angle thatmatches the angle of the tapered wall 340 and 356 of the fluid routingplug 116. Thus, the sealing surfaces 420 and 422 each taper at an angleof 30 or 45 degrees. Preferably, the tapered walls 340 and 356 and thesealing surfaces 420 and 422 both taper at an angle of 45 degrees.

Forming the mating tapered walls 340 and 356 and sealing surfaces 420and 422 at 45 degrees provides more surface area for the valves 292 and294 to seal against the fluid routing plug 116. Providing more sealingsurface area or a larger “strike face” helps distribute the forcesapplied to the valves 292 and 294 and the fluid routing plug 116,thereby providing more evenly distributed sealing. Providing more evenlydistributed sealing prevents certain areas from wearing faster thanothers, helping to increase the life of the parts.

Each valve 292 and 294 also has an outer sealing diameter A and an innersealing diameter B, as shown in FIGS. 72 and 85 . The ratio of the outersealing diameter A to the inner sealing diameter B is preferably 1.55 orgreater. This ratio helps increase the life of the valves 292 and 294and reduce any turbulent fluid flow during operation. The valves 292 and294 and the fluid routing plug 116 are configured so that no portion ofthe valves 292 and 294 enters the first or second fluid passages 326 and336 during operation. Additionally, no portion of the valve 292 entersthe blind bore 328 during operation. Rather, the suction valve 292 isconfigured only to cover the entrance 342 of the blind bore 330 on thefirst surface 318, and the discharge valve 294 is configured only tocover the openings 364 of the second fluid passages 336 on the secondsurface 320.

Continuing with FIGS. 72-76 , the suction valve 292 is shown in moredetail. The suction valve 292 comprises the sealing element 346 joinedto a stem 424. When the suction valve 292 is installed within thehorizontal bore 106, the stem 424 extends along an axis that is parallelto or aligned with central the longitudinal axis 114 of the housing 104.

The sealing element 346 comprises opposed first and second surfaces 426and 428 joined by the sealing surface 420. A groove 430 is formed in thesealing surface 420 adjacent the first surface 426, as shown in FIG. 76. A seal 432 is installed within the groove 430. The groove 430 ischaracterized by a first sidewall 434 joined to a second sidewall 436.The sidewalls 434 and 436 may be joined by an inner groove 438. Thegroove 430 is sized to correspond with the inward facing surface of theseal 432. An outward facing surface of the seal 432 comprises a convexsurface 440 joined to a concave surface 442. The seal 432 is preferablymade of a polyurethane compound. In alternative embodiments, the sealmay be made of a different elastomer material.

When the suction valve 296 seals against the first surface 318 of thefluid routing plug 116, the seal 432 and a portion of the sealingsurface 420 mate with the tapered wall 340, as shown in FIG. 51 . Theseal 432 is shaped so that the convex surface 440 displaces into, ortoward, the concave surface 442 as the seal 432 engages the tapered wall340. This relative movement allows the shear forces to be dissipated,increasing the life of the seal 432 and the suction valve 292. If theseal 432 becomes worn and no longer seals properly, the seal 342 may beremoved and replaced with a new seal 432. In alternative embodiments,the seal and groove may have various shapes and sizes, as desired. Infurther alternative embodiments, the sealing surface may not include agroove and corresponding seal.

Continuing with FIG. 76 , the second surface 428 of the sealing element346 is sized to cover the entrance 342 of the blind bore 328, as shownin FIG. 51 . A cutout 444 is formed within the second surface 428. Thecutout 444 creates a small cavity within the second surface 428. Thecavity provides space for fluid to collect and apply pressure to thesuction valve 292. Such pressure helps force the suction valve 292 tomove axially to an open position.

Continuing with FIGS. 75 and 76 , the stem 424 projects from the firstsurface 426 of the sealing element 346. An annular void 446 is formed inthe first surface 426 and surrounds the stem 424. The first surface 426further includes a ring-shaped outer rim 448 that surrounds the annularvoid 446 and the stem 424. The outer rim 448 joins the sealing surface420. The annular void 446 reduces weight within the suction valve 292and helps orient the valve's center of gravity during operation.

An annular groove 450 is formed in the outer rim 448. The groove 450 isconfigured for receiving a bottom portion of a spring 452, as shown inFIG. 83 . As described below, a top portion of the spring 452 engageswith the suction valve guide 296, as shown in FIGS. 83 and 84 . Thespring 452 biases the suction valve 292 in the closed position.Positioning the spring 452 on the outer rim 448 helps to stabilize thesuction valve 292 during operation.

With reference to FIGS. 77-82 , the stem 424 is configured to moveaxially within the suction valve guide 296. The suction valve guide 296may also be referred to as a cage for the suction valve 292. The suctionvalve guide 296 comprises a body 454 having opposed first and secondsurfaces 456 and 458. A central passage 460 is formed within the body454 and interconnects the first and second surfaces 456 and 458. Aplurality of legs 462 extend out from the body 454 adjacent its firstsurface 456 and project downward towards its second surface 458. Thesuction valve guide 296 shown in FIGS. 77-82 has six evenly spaced legs462 formed around its body 454. In alternative embodiments, more or lessthan six legs may be formed on the body and may be non-uniformly spaced.

The legs 462 gradually decrease in thickness from the body 454 to abottom surface 464 of each leg 462. The bottom surface 464 of each leg462 is extremely thin so that the legs 462 do not block or interferewith the openings 348 of the second fluid passages 336 on the firstsurface 318, as shown in FIG. 50 .

Continuing with FIGS. 77-82 , an outer surface of each leg 462 includesa bevel 466. The bevels 466 are configured to engage a correspondingbevel 468 formed in the walls of the housing 104, as shown in FIGS. 50and 51 . The suction valve guide 296 is inserted into the horizontalbore 106 until the bevels 466 and 468 engage, allowing the guide 296 tobottom out on the walls of the housing 104. Once the bevels 466 and 468are engaged, the suction valve guide 296 is held against the walls ofthe housing 104 by the spring 452 and fluid pressure.

When the suction valve guide 296 is in its installed position, thebottom surface 464 of each of the legs 462 hovers just above the firstsurface 318 of the fluid routing plug 116, leaving a gap between thelegs 462 and the plug 116. The bottom surfaces 464 do not directlycontact the fluid routing plug 116 in order to prevent the suction valveguide 296 from applying load to the plug 116 during operation.

Continuing with FIG. 80 , a tubular insert 470 is installed within thecentral passage 460 of the body 454. The insert 470 may be press-fitwithin the passage 460. The insert 470 extends the length of the centralpassage 460 and is formed from a more wear resistant material than thesuction valve guide 296. For example, the insert 470 may be made oftungsten carbide, while the suction valve guide 296 may be made of highstrength alloy steel. The stem 424 is installed within the insert 470and reciprocates within the insert 470 during operation, as shown inFIGS. 50 and 51 . Any fluid contained within the insert 470 drains fromthe opening of the central passage 460 on the first surface 456 of thebody 454.

During operation, the stem 424 may wear against the insert 470 as itreciprocates. The insert 470 helps decrease the rate of wear and helpsthe stem to wear evenly against the insert. Forming only the insert 470out of a wear resistant material helps reduce the cost of the otherparts, that do not experience as much wear during operation.

Turning to FIGS. 83 and 84 , the spring 452 is interposed between thesuction valve 292 and the suction valve guide 296. The spring 452 isheld between the outer rim 448 of the suction valve 292 and an innersurface 472 of the legs 462. At least a portion of the spring 452surrounds the body 454 of the suction valve guide 296. As the suctionvalve 292 moves to an open position, the spring 452 compresses betweenthe suction valve 292 and the suction valve guide 296.

With reference to FIGS. 85-89 , the discharge valve 294 is shown in moredetail. As discussed above, the discharge valve 294 is constructedidentically to the suction valve 292, with the exception that thedischarge valve 294 may be larger in size. The discharge valve 294 shownin FIGS. 85-89 , for example, has a larger sealing surface 422 and alonger stem 474 than the suction valve 292. When the discharge valve 294is installed within the horizontal bore 106, the stem 424 extends alongan axis that is parallel to or aligned with the central longitudinalaxis 114 of the housing 104. A seal 475 is installed within a groove 477formed in the sealing surface 422 and is configured to engage with thetapered wall 356 formed in the second surface 320 of the fluid routingplug 116. A bottom surface 476 of the discharge valve 294 is sized tocover the central base 354, as shown in FIG. 50 .

With reference to FIGS. 90-95 , the stem 474 formed on the dischargevalve 294 is configured to move axially within the discharge valve guide298. The discharge valve guide 298 may also be referred to as a cage forthe discharge valve 294. The discharge valve guide 298 comprises a body478 having opposed first and second surfaces 480 and 482 joined by anintermediate surface 484. The intermediate surface 484 includes a frontportion 486, a medial portion 488, and a rear portion 490. The medialportion 488 has a larger diameter than both the front and rear portions486 and 490. The front portion 486 has a slightly larger diameter thanthe rear portion 490.

Continuing with FIGS. 90-95 , a blind bore 492 is formed in the firstsurface 480 and extends into the front portion 486 of the body 478. Theblind bore 492 is configured to receive a tool used to grip thedischarge valve guide 298. The front portion 486 is sized to be receivedwithin the cutout 308 formed in the retainer 300, as shown in FIGS. 50and 51 . When the discharge valve guide 298 and the retainer 300 areengaged, the blind bore 492 opens into the central passage 310 formed inthe retainer 300.

A central passage 494 is formed in the body 478 and opens on the secondsurface 482, as shown in FIGS. 93 and 94 . The central passage 494 opensin the body 478 into an axially blind counterbore 496. A plurality ofrelief ports 498 are formed in the body 478. Each relief port 498interconnects the counterbore 496 and a base 500 of the medial portion488, as shown in FIG. 94 .

Continuing with FIGS. 93 and 94 , a tubular insert 502 is installedwithin the central passage 494. The insert 502 is identical to theinsert 470, with the exception that the insert 502 may be larger thanthe insert 470. During operation, the stem 474 moves axially within theinsert 502 installed within the central passage 494. Any fluid withinthe insert 502 drains from the body 478 through the counterbore 496 andthe relief ports 498.

Continuing with FIGS. 90-92 , a plurality of legs 504 project from themedial portion 488 and extend towards the second surface 482 of the body478. The discharge valve guide 298 shown in FIGS. 90-95 comprises fivelegs 504. The legs 504 are positioned on the body 478 so as to leave alarge space 506 between at least two adjacent legs 504. Other than thespace 506, the legs 504 are equally spaced from one another. The space506 is intended to align with the discharge bore 178, thereby preventingany legs 504 from blocking the discharge bore 178 during operation.Providing the space 506 therefore allows fluid to flow freely betweenthe discharge valve 294 and the discharge bore 178 without significantobstructions. The space 506 also helps minimize wear applied to the legs504 by the flowing fluid over time. In alternative embodiments, the bodymay have more or less than five legs as be spaced, as desired, as longas the legs are positioned on the body so as to leave a large spacebetween at least two of the legs.

With reference to FIG. 90 , each of the legs 504 has a thicker upperportion 508 and thinner lower portion 510. The thicker upper portion 508provides strength to the legs 504 while the lower portion 510 is thinnedin order to provide more room for fluid flow around the legs 504. Theupper portion 508 also includes a tapered inner surface 512. Taperingthe inner surface 512 of the legs 504 provides strength and alleviatesstress in the legs 504 during operation.

Continuing with FIGS. 90-95 , when the discharge valve guide 298 isinstalled within the horizontal bore 106, a bottom surface 514 of eachleg 504 engages the outer rim 352 of the second surface 320 of the fluidrouting plug 116, as shown in FIGS. 50 and 51 . The discharge valveguide 298 is held against the fluid routing plug 116 by the retainer300. Such engagement helps keep the second bevel 382 of the fluidrouting plug 116 seated against the second beveled surface 384, as shownin FIGS. 65 and 68 .

Continuing with FIGS. 93 and 95 , a dowel pin 516 is installed within ablind bore 517 formed in the medial portion 488 of the body 478. Thedowel pin 516 is configured to be received within a dowel pin hole orgroove 518 formed in the walls of the housing 104 surrounding thehorizontal bore 106, as shown in FIGS. 96 and 97 . The discharge valveguide 298 is installed within the horizontal bore 106 such that thedowel pin 516 is positioned within the dowel pin hole 518. Suchpositioning ensures that the space 506 between the pair of legs 504aligns with the discharge bore 178, thus preventing any legs 504 fromblocking the discharge bore 178 during operation.

Continuing with FIGS. 96 and 97 , a seal 520 is interposed between theintermediate surface 484 of the body 478 and the walls of the housing104. The seal 520 may be identical to the second seal 376 shown in FIGS.65 and 70 . In alternative embodiments, the seal may be identical to thefirst seal 374 shown in FIGS. 65 and 71 . The seal 520 is installedwithin a groove 522 formed in the housing 104. The groove 522 ischaracterized by two sidewalls 524 joined to a base 526. The sidewalls524 may join the base 526 via radius corner or at a 90 degree angle.During operation, the seal 520 wears against the outer intermediatesurface 484 of the discharge valve guide 298. If the intermediatesurface 484 begins to erode, allowing fluid to leak around the seal 520,the discharge valve guide 298 may be removed and replaced with a newdischarge valve guide 298.

With reference to FIGS. 98 and 99 , a spring 528 is installed betweenthe discharge valve 294 and the discharge valve guide 298. A bottomportion of the spring 528 sits in a groove 530, shown in FIG. 89 ,formed in an outer rim 532 of the discharge valve 294. A top portion ofthe spring 528 engages a ledge 534 formed in the base 500 of the medialportion 488 of the discharge valve guide 298. During operation, thespring 528 compresses against the ledge 534 of the medial portion 488.

Turning to FIG. 100 , the components installed within the housing 104are installed through the first surface 108, starting with the suctionvalve guide 296. The diameter of the installed components slightlyincreases from the second surface 320 to the first surface 318. Forexample, the suction valve guide 296 has smaller outer diameters thanthe fluid routing plug 116, and the fluid routing plug 116 has smallerouter diameters than the discharge valve guide 298. The discharge valveguide 298 has smaller outer diameters than the retainer 300.

Likewise, the diameters of the walls surrounding the horizontal bore 106generally increase from the second surface 110 to the first surface 108.As shown in FIG. 100 , a diameter D₄ of the horizontal bore 106 isgreater than a diameter D₃ of the horizontal bore 106. The diameter D₃of the horizontal bore 106 is greater than a diameter D₂ of thehorizontal bore 106. The diameter D₂ of the horizontal bore 106 isgreater than a diameter Di of the horizontal bore 106. Such constructionallows the components to be installed without engaging the walls of thehousing 104 until the component is at its intended installed position.The seals 374, 376, and 520 may be installed within the housing 104prior to installing the other components described above.

Turning to FIGS. 100A-100E, another embodiment of a fluid routing plug550 is shown. The fluid routing plug 550 may be installed within thehousing 104 in place of the fluid routing plug 116. The fluid routingplug 550 is identical to the fluid routing plug 116, with a fewexceptions. The fluid routing plug 550 comprises a body 552 having afirst outer surface 554 joined to a second outer surface 556 by anintermediate outer surface 558. The second surface 556 of the fluidrouting plug 550 generally identical to the second surface 320 of thefluid routing plug 116, but a central base 560 formed in the secondsurface 556 is spaced from an edge 562 of a tapered wall 564 formed inthe second surface 556. The central base 560 is spaced from the taperedwall 564 such that a throat 566 is formed between the central base 560and the tapered wall 564.

Continuing with FIGS. 100A-100D, a blind hole 568 is formed in thecentral base 560 and a plurality of openings 570 corresponding to aplurality of second fluid passages 572 open on the central base 560 andsurround the blind hole 568. In operation, fluid exiting the openings570 flows into the throat 566 before pushing against the discharge valve294 engaged with the second surface 556. Allowing fluid to gather in thethroat 566 before contacting the discharge valve 294 helps the fluid tocontact more surface area of the discharge valve 294, instead of havinga plurality of single points of contact from each second fluid passageopening. Allowing the fluid to contact more surface area of thedischarge valve 294 helps reduce wear to the valve over time.

Continuing with FIGS. 100E and 100F, the intermediate surface 558 of thefluid routing plug 550 is identical to the intermediate surface 322formed on the fluid routing plug 116. However, the intermediate surface558 may include a cutout 576 adjacent the second surface 556. The cutout576 provides space for fluid or proppant to collect during operation, asshown in FIG. 100F. The cutout 576 also helps reduce friction duringinstallation of the fluid routing plug 550 within the housing 104. Asmall gap 578 may also exist between the walls of the housing 104 andthe intermediate surface 558 between a second sealing surface 580 andthe cutout 576, as shown in FIG. 100F. The gap 578 helps the seal 376breath during operation.

Continuing with FIG. 100B, the first surface 554 of the fluid routingplug 550 is identical of the first surface 318 of the fluid routing plug116, with the exception of its outer rim 582. The outer rim 582 is flatand wider than the outer rim 338, shown in FIG. 55 . Because the outerrim 582 is wider, a plurality of openings 584 for the second fluidpassages 572 may have a slightly larger diameter than the openings 348,shown in FIG. 56 . Likewise, the openings 570 may also have a slightlylarger diameter than the openings 364 shown in FIG. 54 . Providing aslightly larger diameter for the second fluid passages 572 helps reducefluid velocity through the fluid routing plug 550 during operation.Reducing fluid velocity within the fluid routing plug 550 helps reducewear to the fluid routing plug 550 over time.

Turning to FIGS. 101-109 , another embodiment of a fluid routing plug600 is shown. The fluid routing plug 600 may be installed within thehousing 104 in place of the fluid routing plug 116. The fluid routingplug 600 is identical to the fluid routing plug 116, with a fewexceptions. The fluid routing plug 600 comprises a body 602 having afirst outer surface 604 joined to a second outer surface 606 by anintermediate outer surface 608. In contrast to the fluid routing plug116, the first and second surfaces 604 and 606 of the fluid routing plug600 are configured so that each surface 604 and 606 has identicallysized tapered walls 610 and 612, as shown in FIG. 103 . Because thetapered walls 610 and 612 are the same size, a suction valve 614 and adischarge valve 616 used with the fluid routing plug 600 may beidentical in size, as shown in FIGS. 108 and 109 .

Using the same size suction and discharge valves 614 and 616 helpsequalize the forces applied to the fluid routing plug 600 and the valves614 and 616 during operation, helping to reduce any wear to the partsover time. Making the suction and discharge valves 614 and 616 identicalalso makes replacing the valves 614 and 616 during operation easier.

Continuing with FIGS. 103, 105, and 106 , the tapered wall 612 formed inthe second surface 606 extends between an outer rim 618 and an annulargroove 620 formed in the center of the second surface 606. The annulargroove 620 may be considered a central base formed in the second surface606. The groove 620 surrounds a blind bore 622 formed in the center ofthe second surface 606. The blind bore 622 is identical to the blindbore 362 formed in the fluid routing plug 116, as shown in FIG. 55 .

The groove 620 is characterized by two parallel sidewalls 624 joined bya base 626. The sidewalls 624 each extend at a non-zero angle relativeto a central longitudinal axis 628 of the body 602. Because thesidewalls 624 of the groove 620 extend at an angle, the base 626 of thegroove 620 extends at a non-zero angle relative to the centrallongitudinal axis 628 of the body 602. Preferably, the base 626 extendsat approximately the same angle as the tapered wall 612 so that the base626 and the tapered wall 612 are in a generally parallel relationship.The tapered wall 612 shown in FIG. 103 extends at a 45 degree anglerelative to the central longitudinal axis 628.

An annular inner edge 638 of the tapered wall 612 is joined to the outersidewall 624 of the groove 620 at a right angle. The diameter of theinner edge 638 of the tapered wall 612 is the same size as a diameter ofan entrance 630 of an axially blind bore 632 formed in the first surface604, as shown in FIG. 103 . In alternative embodiments, the grooveformed in the second surface and the inner edge of the tapered wall maynot have an annular shape.

Continuing with FIGS. 103, 105, and 106 , a plurality of second fluidpassages 634 are formed in the body 602. The second fluid passages 634are identical to the second fluid passages 336 formed in the fluidrouting plug 116, shown in FIGS. 52-64 , with the exception of thepositioning of their openings 636 on the second surface 606. Each secondfluid passage 634 opens on the base 626 of the groove 620 formed in thesecond surface 606. Thus, the openings 636 are axially spaced from theinner edge 638 of the tapered wall 612. Because the sidewalls 624 of thegroove 620 are formed at an angle, the inner edge 638 of the taperedwall 612 slightly overlaps the openings 636, as shown in FIG. 106 . Bypositioning the openings 636 in an axially spaced relationship with theinner edge 638 of the tapered wall 612, the size of the tapered wall 612can be decreased without decreasing the size of the openings 636. Theannular groove 620 also functions as a throat, similar to the throat 566formed in the fluid routing plug 550.

Because the tapered wall 612 is decreased in size from the tapered wall356 shown in FIG. 55 , the outer rim 618 on the second surface 606 iswider than the outer rim 352. The outer rim 618 also tapers between theintermediate surface 608 and the tapered wall 612, as shown in FIGS. 103and 104 . Such taper increases the length of the tapered wall 612without increasing the length of the intermediate surface 608.

Continuing with FIGS. 101-107 , the first surface 604 is identical tothe first surface 318 shown in FIGS. 53, 55, and 56 , with the exceptionof its outer rim 640. Instead of tapering like the outer rim 338, shownin FIG. 55 , the outer rim 640 is flat. The outer rim 640 is flat inorder to slightly decrease the size of the tapered wall 610 to match thesize of the tapered wall 612. The intermediate surface 608 of the fluidrouting plug 600 is identical to that of the fluid routing plug 116,shown in FIG. 64 . A plurality of first fluid passages 642 formed in thebody 602 are identical to the first fluid passages 326, shown in FIGS.55, 57, and 59 . The second fluid passages 634 open on the outer rim 640of the first surface 604, as shown by the openings 644. The openings 644are positioned in groups 645, in the same manner as the second fluidpassages 336 formed in the fluid routing plug 116, as shown in FIG. 56 .The openings 636 on the second surface 606 may remain spaced in groups645, as shown in FIG. 106 .

With reference to FIGS. 108 and 109 , the fluid routing plug 600 routesfluid throughout the housing 104 in the same manner as the fluid routingplug 116. The suction valve guide 296 is shown engaged with suctionvalve 614. Another embodiment of a discharge valve guide 647 is shownengaged with the discharge valve 616.

The discharge valve guide 647 is identical to the discharge valve guide298, shown in FIGS. 90-95 , with a few exceptions. A counterbore 649formed in the guide 647 is larger than the counterbore 496. Thecounterbore 649 is larger in order to accommodate the shorter stem 646of the discharge valve 616. An insert 651 installed within the dischargevalve guide 647 is the same size as the insert 470 installed within thesuction valve guide 296.

With reference to FIGS. 110-114 , as discussed above, in contrast to thevalves 292 and 294, the valves 614 and 616 are identical in size andshape. The valves 614 and 616 are generally identical to the valves 292and 294, with a few exceptions. Each valve 614 and 616 comprises asealing element 652 joined to a stem 646. The stem 646 projects from afirst surface 650 of the sealing element 652.

An annular cutout 648 is formed within a medial portion of the stem 646.The cutout 648 provides space for fluid or proppants to collect duringoperation. Providing such space prevents the fluid and proppants fromrubbing against the inserts 470 and 502. The suction and dischargevalves 292 and 294 may be configured to include an annular cutout withintheir stems 424 and 474.

Continuing with FIGS. 110-114 , the sealing element 652 further includesa second surface 668 joined to the first surface 650 by a sealingsurface 658. A groove 656 is formed in the sealing surface 658 forhousing a seal 654. The groove 656 is identical to the groove 430, shownin FIG. 76 . An outward facing surface of the seal 654 comprises asidewall 660 joined to a tapered base 662. In operation, the taperedbase 662 engages the tapered walls 610 and 612 of the fluid routing plug600. The sidewall 660 may compress creating a tight seal.

The first surface 650 of the sealing element 652 includes an outer rim664. An outer ledge 666 surrounds the outer rim 664. A bottom portion ofa spring engages the outer rim 664 and is held in place by the outerledge 666. While not shown, a cutout may be formed in the second surface668 of the sealing element 652, like the cutout 444, shown in FIG. 76 .

One or more kits may be useful in assembling the fluid end section 102.A kit may comprise a plurality of housings 104 and a plurality of thecorresponding fluid routing plugs 116, 550, or 600. The kit may alsocomprise a plurality of suction valves 292 or 614, discharge valves 294or 616, suction valve guides 296, discharge valve guides 298 or 657,springs 452 and 528, retainer 300, stuffing box 140, retainer 232,plunger packing 224, packing nut 276, fastening system 234, dischargeconduit 174, and the various seals described herein. The kit may alsocomprise the intake manifolds 166 and 168, pipe system 176, connectplate 118, fastening system 146 and stay rods 120. The kit may alsocomprise other various features described herein for use with the fluidend 100. Unless specifically described herein, the various components ofthe fluid end 100 may be made of high strength alloy steel, such ascarbon steel or stainless steel.

With reference to FIGS. 115-117 , an alternative embodiment of a fluidrouting plug 700 is shown. The fluid routing plug 700 may be installedwithin the housing 104 in place of the fluid routing plug 116. The fluidrouting plug 700 is identical to the fluid routing plug 116, with theexception of the shape of its first and second bevels 702 and 704. Whenthe fluid routing plug 700 is first installed within the horizontal bore106, the second bevel 704 only partially engages a second beveledsurface 706, as shown in FIG. 116 . The bevels 704 and 706 mate at asecond bevel mating surface 708 and a second beveled surface matingsurface 710. Below the mating surfaces 708 and 710, the second bevel 704and the second beveled surface 706 have mating angles that are notequal, causing a gap 712 to exist between the bevels 704 and 706.Specifically, the second bevel 704 may have a slightly convex shape sothat portions of the second bevel 704 don't match the flat shape of thesecond beveled surface 706.

The width of the gap 712 gradually increases between the mating surfaces708 and 710 and a bottom portion 714 of the second bevel 704 and abottom portion 716 of the second beveled surface 706. Thus, the width Bof the gap 712 is wider than the width A of the gap 712. Because thesecond bevel 704 has a slightly convex shape, the angle between themating surfaces 708 and 710 is different from the angle between thebottom portions 714 and 716.

Turning to FIG. 117 , the first bevel 702 and the first beveled surface718 are shown in more detail. Like the second bevel 704, the first bevel702 may only partially engage a first beveled surface 718. The bevels702 and 718 mate at a first bevel mating surface 720 and a first beveledsurface mating surface 722. Below the mating surfaces 720 and 722, thefirst bevel 702 and the first beveled surface 718 have mating anglesthat are not equal, causing a gap 724 to exist between the bevels 702and 718. Specifically, the first bevel 702 may have a slightly convexshape so that portions of the first bevel 702 do not match the flatshape of the first beveled surface 718.

The width of the gap 724 gradually increases between the mating surfaces720 and 722 and a bottom portion 726 of the first bevel 702 and a bottomportion 728 of the first beveled surface 718. Thus, the width B of thegap 724 is wider than the width A of the gap 724. Because the firstbevel 702 has a slightly convex shape, the angle between the matingsurfaces 720 and 722 is different from the angle between the bottomportions 726 and 728.

The width of the gaps 712 and 724 has been exaggerated in FIGS. 116 and117 for illustration purposes. In reality, portions of the gaps 712 and724 may be approximately 0.002 inches in width, for example. However,the gaps 712 and 724 may be wider or smaller depending on the materialsand forces used.

As discussed above, in operation, the fluid pressure applied to thefluid routing plug 700 will cause the plug 700 to compress and expand asthe plunger 290 retracts from the housing 104. As the fluid routing plug700 starts to expand, the bottom portion 714 of the second bevel 704will move to engage the bottom portion 714 of the second beveled surface706, causing the bottom portions 714 and 716 to mate. Likewise, thebottom portion 726 of the first bevel 702 will move to engage the bottomportion 728 of the first beveled surface 718. Such movement of the fluidrouting plug 700 distributes the load applied to the fluid routing plug700 through the length of the first and second bevels 702 and 704.

With reference to FIGS. 118-120 , an alternative embodiment of a fluidrouting plug 800 is shown. The fluid routing plug 800 may be installedwithin the housing 104 in place of the fluid routing plug 116. The fluidrouting plug 800 is identical to the fluid routing plug 700, with theexception of the shape of its first and second bevels 802 and 804. Likethe fluid routing plug 700, the second bevel 804 is sized to leave a gap806 between the second bevel 804 and a second beveled surface 808 whenthe fluid routing plug 800 is first installed within the housing 104. Incontrast to the gap 712, an angle formed between the mating surfaces 810and 812 and bottom portions 814 and 816 of the second bevel 804 andsecond beveled surface 808 remains the same. Thus, an area A of the gap806 has the same angle as an area B of the gap 806.

Likewise, the first bevel 802 is shaped so that an angle formed betweenthe first bevel 802 and a first beveled surface 820 stays relatively thesame between mating surfaces 822 and 824 and bottom portions 826 and828. Thus, the width A of the gap 818 has approximately the same angleas the width B of the gap 818.

The width of the gaps 806 and 818 has been exaggerated in FIGS. 119 and120 for illustration purposes. In reality, portions of the gaps 806 and818, for example, may be approximately 0.002 inches in width. However,the gaps 806 and 818 may be wider or smaller depending on the materialsand forces used.

As discussed above, the first and second bevels 802 and 804 expandduring operation. Such movement of the fluid routing plug 800distributes the load applied to the fluid routing plug 800 through thelength of the first and second bevels 802 and 804.

In alternative embodiments, the first bevel may be configured to have agap that increases in size, as shown in FIG. 117 , while the secondbevel may be configured to have a gap that increases by a differentamount, as shown in FIG. 119 , and vice versa. In further alternativeembodiments, the width of the gap may be of various shapes and sizesdepending on the materials used and forces involved. In even furtheralternative embodiments, the intermediate surface of the fluid routingplug may include any combination of the different bevel constructionsdescribed herein.

Turning to FIGS. 121-128 , another embodiment of a fluid routing plug900 is shown. The fluid routing plug 900 may be installed within thehousing 104 in place of the fluid routing plug 116. The fluid routingplug 900 is identical to the fluid routing plug 116, with a fewexceptions. The fluid routing plug 900 comprises a body 902 having afirst outer surface 904 joined to a second outer surface 906 by anintermediate outer surface 908. A plurality of first fluid passages 910are formed in the body 902 and interconnect the intermediate surface 908and the first surface 904 by way of an axially blind bore 912, as shownin FIG. 124 .

In contrast to the first fluid passages 326, shown in FIGS. 55 and 58 ,a longitudinal axis 914 of each first fluid passage 910 does notintersect a central longitudinal axis 916 of the body 902, as shown inFIG. 125 . Rather, the first fluid passages 910 are formed such that thelongitudinal axis 914 of each passage 910 is offset from the centrallongitudinal axis 916 of body 902. The offset configuration of the firstfluid passages 910 encourages a vortex type flow of fluid about thecentral longitudinal axis 916, thereby reducing fluid turbulence duringoperation. In alternative embodiments, the longitudinal axis 914 of eachfirst fluid passage 910 may intersect the longitudinal axis 916 of thebody 902.

A plurality of openings 918 formed on the intermediate surface 908 forthe first fluid passages 910 are similar to the openings 334, shown inFIGS. 57 and 59 , but have a more oblong shape, as shown in FIG. 121 .The oblong shape shown in FIG. 121 has opposed first and second ends 920and 922. The second end 922, which is closer to the second surface 906,is slightly wider than the first end 920. The unequal size of the ends920 and 922 helps direct fluid along the offset longitudinal axis 914 ofthe first fluid passages 910. The unequal size of the ends 920 and 922also helps increase the wall thickness in certain areas of the body 902between the first fluid passages 910 and a plurality of second fluidpassages 924.

In alternative embodiments, the opposed ends of the openings may beidentical in size or may be shaped identical to the openings 334, shownin FIGS. 57 and 59 . The opening 918 of the first fluid passage 910shown in FIG. 121 extends along an axis that is parallel to thelongitudinal axis 916 of the body 902. In alternative embodiments, theopenings of the first fluid passages may extend at a non-zero anglerelative to the longitudinal axis 916 of the body 902, as shown forexample by the openings 972 shown in FIG. 128D. The angle at which thefirst fluid passages 910 are formed in the body 902 may vary, asdesired, in order to increase the wall thickness within the body 902 andreduce stress in the body 902 during operation.

Continuing with FIGS. 122 and 126 , each of the second fluid passages924 formed in the body 902 interconnects the first and second surfaces904 and 906. The second fluid passages 924 are identical to the secondfluid passages 336, shown in FIGS. 60-63 , but the second fluid passages924 are slightly pivoted from the position of the second fluid passages336. Each second fluid passage 924 is pivoted so that it has a compoundangle with respect to the central longitudinal axis 916, as shown inFIGS. 122, 123 126, and 127. Meaning, each second fluid passage 924extends such that it has two different angles relative to the centrallongitudinal axis 916—up-and-down, and side-to-side. Like the firstfluid passages 910, forming the second fluid passages 924 at such anglesencourages a vortex type flow of fluid about the central longitudinalaxis 916, thereby reducing fluid turbulence during operation.

Continuing with FIGS. 124, 127, and 128 , the first surface 904 of thefluid routing plug 900 may be identical to the first surface 318, shownin FIGS. 53, 55, and 56 . However, an outer rim 926 of the first surface904 may be flat rather than tapered. The second surface 906 of the fluidrouting plug 900 is identical to the fluid routing plug 116, but acentral base 928 formed in the second surface 906 may be slightly setback within the body 902, as compared to the central base 354, shown inFIGS. 54 and 55 . An outer rim 930 on the second surface 906 may beslightly wider than the outer rim 352, shown in FIGS. 54 and 55 . Theintermediate surface 908 of the fluid routing plug 900 may be identicalto the intermediate surface 322 of the fluid routing plug 116.Alternatively the intermediate surface may be identical to those formedon the fluid routing plug 700 or 800.

In alternative embodiments, the first and second surfaces 904 and 906 ofthe fluid routing plug 900 may be configured so that its tapered walls932 and 934 are the same size, like the fluid routing plug 600. Infurther alternative embodiments, the first and second surfaces of thefluid routing plug 900 may be identical to the first and second surfacesof the fluid routing plug 116.

Turning to FIGS. 128A-128G, another embodiment of a fluid routing plug950 is shown. The fluid routing plug 950 may be installed within thehousing 104 in place of the fluid routing plug 116. The fluid routingplug 950 is identical to the fluid routing plug 900, with a fewexceptions. The fluid routing plug 950 comprises a body 962 having afirst outer surface 964 joined to a second outer surface 952 by anintermediate outer surface 966. In contrast to the fluid routing plug900, the second surface 952 of the fluid routing plug 950 is formedidentically to the second surface 856 of the fluid routing plug 850,shown in FIGS. 100A-100E. A central base 954 formed in the secondsurface 952 is spaced from an edge 956 of a tapered wall 958 such that athroat 960 is formed within the second surface 952. The throat 960serves the same purpose as the throat 566 formed in the fluid routingplug 550.

Continuing with FIG. 128A-128G, a plurality of first fluid passages 968,shown in FIG. 128G, and a plurality of second fluid passages 970, shownin FIG. 128A, are formed in the body 962. The first and second fluidpassages 968 and 970 are identical to the first and second passages 910and 924 formed in the fluid routing plug 900. However, as discussedabove, an opening 972 of the first fluid passages 968 may extend along anon-zero angle relative to a central longitudinal axis 974 of the body962, as shown in FIG. 128D. In alternative embodiments, the openings 972may be identical to the openings 918, shown in FIG. 121 . Like the fluidrouting plug 900, the angle at which the first fluid passages 968 areformed in the body 962 may vary, as desired, in order to increase thewall thickness within the body 962 and reduce stress in the body 962during operation.

In alternative embodiments, the first and second surfaces 964 and 952 ofthe fluid routing plug 950 may be configured like the fluid routing plug600. In further alternative embodiments, the first and second surfacesof the fluid routing plug 950 may be identical to the first and secondsurfaces of the fluid routing plug 116.

Turning to FIGS. 129-131 , another embodiment of a fluid routing plug1000 is shown. The fluid routing plug 1000 may be installed within thehousing 104 in place of the fluid routing plug 116. The fluid routingplug 1000 is identical to the fluid routing plug 116, but includes afirst and second annular recess 1002 and 1004 formed in its intermediatesurface 1001. The first annular recess 1002 is positioned between afirst bevel 1006 and a first sealing surface 1008. The second annularrecess 1004 is positioned between a second sealing surface 1010 and asecond bevel 1012.

When the fluid routing plug 1000 is installed within the horizontal bore106, a small annular space exists between the wall of the housing 104and each recess 1002 and 1004. The space provides relief areas forexcess fluid or proppant to collect during operation. The first andsecond recesses 1002 and 1004 may also be formed in the intermediatesurfaces of the fluid routing plugs 550, 600, 700, 800, 900, and 950.

In alternative embodiments, the first and second surfaces of each of thefluid routing plugs 550, 600, 700, 800, 900, and 950 may each be sizedso as to engage with identically sized suction and discharge valves 292,294, 614 or 616, as discussed with regard to fluid routing plug 600. Infurther alternative embodiments, the first and second surfaces of eachof the fluid routing plugs 550, 600, 700, 800, 900, and 950 may be sizedso as to engage with differently sized suction and discharge valves 292,294, 614 or 616. In such embodiment, the valves 292, 294, 614 or 616 maybe sized as desired, as long as the ratio of the outer sealing diameterA to the inner sealing diameter B of each valve is preferably 1.55 orgreater, as discussed with regard to FIGS. 72 and 85 . The desired sizeof the valve may vary depending on the desired fluid velocity within thecorresponding fluid routing plug.

With reference to FIGS. 132 and 133 , another embodiment of a fluid endsection 1100 is shown. The fluid end section 1100 is similar to thefluid end section 102, but comprises another embodiment of a housing1102. The housing 1102 is similar to the housing 104, with the exceptionof its first surface 1104. Rather than having a retainer threaded intoits first surface 1104, like the housing 104, a retainer 1106 isattached to the first surface 1104 of the housing 1102 using a fasteningsystem 1108.

With reference to FIGS. 134-137 , the retainer 1106 comprises a firstsurface 1110 joined to a second surface 1112 by an intermediate surface1114. A central passage 1116 is formed in the retainer 1106 andinterconnects the first and second surfaces 1110 and 1112. The wallssurrounding the central passage 1116 are threaded. A plurality ofpassages 1118 are formed in the retainer 1106 and surround the centralpassage 1116. Each passage 1118 interconnects the first and secondsurfaces 1110 and 1112 of the retainer 1106.

With reference to FIG. 138 , a plurality of threaded openings 1120 areformed in the first surface 1104 of the housing 1102. The openings 1120surround an opening of a horizontal bore 1122 formed in the housing1102. The passages 1118 formed in the retainer 1106 are alignable withthe openings 1120 in a one-to-one relationship. A dowel pin groove 1124is also formed in the housing 1102 adjacent the opening of thehorizontal bore 1122, as shown in FIG. 139 . The dowel pin groove 1124is configured to receive a dowel pin installed within the retainer 1106.The dowel pin helps properly align the retainer 1106 on the firstsurface 1104 of the housing 1102.

Turning back to FIGS. 132 and 133 , the fastening system 1108 comprisesa plurality of studs 1126, washers 1128, and nuts 1130. A first end 1132of each stud 1126 mates with one of the openings 1120 formed in thehousing 1102, in a one-to-one relationship. The passages 1116 formed inthe retainer 1106 subsequently receive the plural studs 1126 projectingfrom the first surface 1104 of the housing 1102.

When the housing 1102 and the retainer 1106 are brought together, asecond end 1134 of each stud 1126 projects from the first surface 1110of the retainer 1106. A washer 1128 and a nut 1130 are subsequentlyinstalled on the second end 1134 of each stud 1126, in a one-to-onerelationship. The nut 1130 is turned until it tightly engages the washer1128 and the first surface 1110 of the retainer 1106, thereby securingthe housing 1102 and the retainer 1106 together. Rather than applying asingle large torque to a single retainer, the fastening system 1108contemplates distribution of smaller torques among a plurality of studs1126 and nuts 1130.

A retainer nut 1136 is threaded into the central passage 1116 formed inthe retainer 1106. The shape and construction of the retainer nut 1136is identical to the shape and construction of retainer 300 shown inFIGS. 47-49 . Rather than remove all of the nuts 1130 and washers 1128,the operator can simply remove the retainer nut 1136. When the retainernut 1136 is removed, the operator can access the interior of the housing1102 through the central passage 1116 of the retainer 1106. Should anyfatigue failures occur between the retainer 1106 and the retainer nut1136, the retainer 1106 and/or retainer nut 1136 may be removed andreplaced with a new retainer 1106 or retainer nut 1136.

Continuing with FIG. 133 , another embodiment of a fluid routing plug1138 is shown installed within the housing 1102. The walls surroundingthe horizontal bore 1122 formed in the housing 1102 are configured tomate with the fluid routing plug 1138. Fluid is routed throughout thefluid routing plug 1138 and the housing 1102 in the same manner as thefluid routing plug 116 and the housing 104, shown in FIGS. 50 and 51 .The fluid routing plug 1138 is described in more detail in U.S. patentapplication Ser. No. 16/951,605, authored by Thomas et al. and filed onNov. 18, 2020, the entire contents of which are incorporated herein byreference.

In alternative embodiments, one of the other fluid routing plugsdescribed herein or described in U.S. patent application Ser. No.16/951,605, authored by Thomas et al. and filed on Nov. 18, 2020, may beinstalled within the housing 1102. In such embodiments, the housing 1102may be configured to receive the chosen fluid routing plug.

Continuing with FIGS. 132 and 133 , the stuffing box 140 andcorresponding components are shown attached to a second surface 1140 ofthe housing 1102. The connect plate 118 is also shown attached to thehousing 1102 in FIG. 132 . A plurality of notches are not shown formedin the housing 1102 adjacent its second surface 1140. In alternativeembodiments, the housing 1102 may include a plurality of notches, likethe notches 136 shown in FIG. 6 .

With reference to FIGS. 140 and 141 , another embodiment of a fluid endsection 1200 is shown. The fluid end section 1200 comprises anotherembodiment of a housing 1202. The housing 1202 is generally identical tothe housing 1102, but comprises a first section 1204 joined to a secondsection 1206 by a fastening system 1208. A discharge bore 1210 is formedin the first section 1204 and a pair of intake bores 1212 and 1214 areformed in the second section 1206, as shown in FIG. 140 . The firstsection 1204 joins the second section 1206 between the discharge bore1210 and the intake bores 1212 and 1214.

With reference to FIGS. 142-148 , the first section 1204 comprises afirst surface 1216 joined to a second surface 1218 by an intermediatesurface 1220. A horizontal bore 1222 extends through the first section1204 and interconnects the first and second surfaces 1216 and 1218.Internal threads 1217 are formed in the walls of the first section 1204surrounding the horizontal bore 1222 adjacent the first surface 1216, asshown in FIGS. 143 and 145 .

The intermediate surface 1220 of the first section 1204 includes a firstportion 1224 joined to a second portion 1226. The second portion 1226has a reduced diameter from that of the first portion 1224 and ispositioned adjacent the second surface 1218 of the first section 1204. Aplurality of passages 1223 are formed in the first section 1204 andsurround the horizontal bore 1222. Each passage 1223 interconnects thefirst surface 1216 and a base 1219 of the first portion 1224.

With reference to FIGS. 149-152 , the second section 1206 comprises afirst surface 1228 joined to a second surface 1230 by an intermediatesurface 1232. A horizontal bore 1234 extends through the second section1206 and interconnects the first and second surfaces 1228 and 1230. Acounterbore 1235 is formed in the first surface 1228 of the secondsection 1206 that is sized to fittingly receive the second portion 1226of the first section 1204. A plurality of threaded openings 1233 areformed in the first surface 1228 of the second section 1206 and surroundthe horizontal bore 1234. The openings 1233 are alignable with thepassages 1223, in a one-to-one-relationship.

Turning back to FIG. 140 , when the second portion 1226 is installedwithin the counterbore 1235, the base 1219 of the first portion 1224abuts the first surface 1228 of the second section 1206. A seal 1238 isinterposed between an outer surface of the second portion 1226 and thewalls of the second section 1206 surrounding the counterbore 1235. Theseal 1238 is installed within a groove 1240 formed in the walls of thesecond section 1206 surrounding the counterbore 1235, as shown in FIGS.149 and 152 . The seal 1238 and groove 1240 may be identical to the seal376 and the groove 406, shown in FIG. 70 .

Continuing with FIG. 141 , the fastening system 1208 comprises aplurality of studs 1242, nuts 1244, and washers 1246. The fasteningsystem 1208 attaches the first section 1204 to the second section 1206in the same fashion as the fastening system 1108 attaches the retainer1106 to the housing 1102, shown in FIG. 133 . A first end 1248 of eachstud 1242 is configured to mate with the openings 1233 formed in thefirst surface 1228 of the second section 1206, in a one-to-onerelationship. The passages 1223 formed in the first section 1204subsequently receive the plurality of studs 1242 projecting from thefirst surface 1228. A nut 1244 and washer 1246 are subsequentlyinstalled on a second end 1250 of each stud 1242 and is turned until thefirst section 1204 and the second section 1206 are secured together.

In operation, the second section 1206 experiences higher fluid pressureand therefore more stress than the first section 1204. Thus, the firstsection 1204 may be made of a lower strength and less costly materialthan the second section 1206. If any failures occur in the first section1204 during operation, the first section may be removed and replacedwith a new first section 1204. Likewise, if any failures occur in thesecond section 1206 during operation, the second section can be removedand replaced with a new second section 1206.

Continuing with FIGS. 140 and 141 , the stuffing box 140 andcorresponding components are shown attached to the second surface 1230of the second section 1206. The fluid routing plug 1138 is showninstalled within both the first and second sections 1204 and 1206. Thewalls surrounding the aligned horizontal bores 1222 and 1234 areconfigured to mate with the fluid routing plug 1138. Fluid is routedthroughout the fluid routing plug 1138 and the first and second sections1204 and 1206 in the same manner as the fluid routing plug 116 and thehousing 104, shown in FIGS. 50 and 51 .

In alternative embodiments, one of the other fluid routing plugsdescribed herein or described U.S. patent application Ser. No.16/951,605, authored by Thomas et al. and filed on Nov. 18, 2020, may beinstalled within the first and second sections 1204 and 1206. In suchembodiments, the first and second sections 1204 and 1206 may beconfigured to receive the chosen fluid routing plug.

With reference to FIG. 153 , another embodiment of a fluid end section1300 is shown. The fluid end section 1300 comprises another embodimentof a housing 1302. The housing 1302 comprises a first surface 1304joined to a second surface 1306 by an intermediate surface 1308. Ahorizontal bore 1305 is formed in the housing 1302 and interconnects thefirst and second surfaces 1304 and 1306.

With reference to FIGS. 154-157 , the intermediate surface 1308 of thehousing 1302 includes a first portion 1310 joined to a second portion1312. The second portion 1312 has a reduced diameter from that of thefirst portion 1310 and includes the second surface 1306 of the housing1302. The first portion 1310 includes varying diameter sections and hasan asymmetrical cross-sectional shape, as shown in FIGS. 156 and 159 .The varying diameter sections and asymmetrical shape are due to portionsof the first portion 1310 being removed. Portions of the first portion1310 have been removed in order to remove excess weight from the housing1302, thereby making the housing 1302 easier to move during assembly.

With reference to FIGS. 160 and 161 , the second portion 1312 of thehousing 1302 is sized to receive another embodiment of a stuffing box1314. A tapered wall 1316 is formed in the second portion 1312 thatextends between the horizontal bore 1305 and the second surface 1306.

With reference to FIGS. 162-165 , the stuffing box 1314 is identical tothe stuffing box 140, but has a first portion 1318 joined to a secondportion 1320 by a tapered portion 1322. A plurality of passages 1324formed in the second portion 1312. Each passage 1324 interconnects asecond surface 1319 of the stuffing box 1314 and the tapered portion1318. The tapered portion 1318 conforms to the tapered wall 1316 formedin the second surface 1306 of the housing 1302. The stuffing box 1314 isattached to the housing 1302 in the same manner as the stuffing box 140,shown in FIGS. 20 and 21 .

Continuing with FIG. 160 , another embodiment of a connect plate 1326 isattached to the housing 1302. A central bore 1328 formed in the connectplate 1326 is sized to receive the second portion 1312 of the housing1302 and at least a portion of the stuffing box 1314. The connect plate1326 is attached to the housing 1302 in the same manner as the connectplate 118, shown in FIG. 17 . The connect plate 1326 is shown anddescribed in more detail in U.S. Provisional Patent Application Ser. No.63/053,797, authored by Thomas et al. and filed on Jul. 20, 2020.

Turning back to FIG. 153 , a discharge bore 1329 formed in the housing1302 interconnects a bottom surface 1330 of the intermediate surface1308 and the horizontal bore 1305. Likewise, a discharge conduit 1332 isshown attached to the bottom surface 1330 of the housing 1302. Inalternative embodiments, the discharge bore may interconnect a topsurface of the housing and the horizontal bore, like the discharge bore178 shown in FIG. 9 . In such embodiment, the discharge conduit isattached to the top surface of the housing, like the discharge conduit174, shown in FIG. 9 .

Continuing with FIG. 153 , another embodiment of a fluid routing plug1334 is shown installed within the housing 1302. The walls surroundingthe horizontal bore 1305 formed in the housing 1302 are configured tomate with the fluid routing plug 1334. Fluid is routed throughout thefluid routing plug 1334 and the housing 1302 in the same manner as thefluid routing plug 116 and the housing 104, shown in FIGS. 50 and 51 .The fluid routing plug 1334 is described in more detail in U.S. patentapplication Ser. No. 16/951,605, authored by Thomas et al. and filed onNov. 18, 2020.

In alternative embodiments, one of the other fluid routing plugsdescribed herein or described in U.S. patent application Ser. No.16/951,605, authored by Thomas et al. and filed on Nov. 18, 2020, may beinstalled within the housing 1302. In such embodiment, the housing 1302may be configured to receive the chosen fluid routing plug.

With reference to FIGS. 166 and 167 , another embodiment of a fluid endsection 1400 is shown. The fluid end section 1400 comprises a housing1402 having a first surface 1406 joined to a second surface 1406 by anintermediate surface 1408. The housing 1402 further comprises anelongate plunger housing 1410 joined to the second surface 1406 of thehousing 1402. A horizontal bore 1412 is formed in the housing thatinterconnects the first surface 1404 and terminal end 1414 of theplunger housing 1410. Only one intake bore 1416 is shown in the housing1402. In alternative embodiments, the housing 1402 may include a secondintake bore.

Continuing with FIG. 167 , the plunger housing 1410 is used in place ofthe stuffing box 140, shown in FIGS. 20 and 21 . The plunger housing1410 is sized to receive an elongate plunger 1418. Fluid is routedthroughout the housing 1402 in the same manner as the housing 104, shownin FIGS. 50 and 51 , but the plunger 1418 has a much longer plungerstroke.

Continuing with FIG. 167 , another embodiment of a fluid routing plug1420 is shown installed within the housing 1402. The walls surroundingthe horizontal bore 1412 formed in the housing 1402 are configured tomate with the fluid routing plug 1420. Fluid is routed throughout thefluid routing plug 1420 and the housing 1402 in the same manner as thefluid routing plug 116 and the housing 104, shown in FIGS. 50 and 51 .The fluid routing plug 1420 is described in more detail in U.S. patentapplication Ser. No. 16/951,605, authored by Thomas et al. and filed onNov. 18, 2020.

In alternative embodiments, one of the other fluid routing plugsdescribed herein or described in U.S. patent application Ser. No.16/951,605, authored by Thomas et al. and filed on Nov. 18, 2020, may beinstalled within the housing 1402. In such embodiment, the housing 1402may be configured to receive the chosen fluid routing plug.

The housings described herein have various embodiments of suctionvalves, discharge valves, suction valve guides, and discharge valveguides. One of skill in the art will appreciate that these componentsmay have various shapes and sizes depending on the construction of thehousing and various components.

While not shown herein, in an alternative embodiment, the fluid end 100described herein may be formed as a single housing having a plurality ofhorizontal bores formed therein and positioned in a side-by-siderelationship. The housing may be attached to a single, large connectplate. In further alternative embodiments, the single housing describedabove may be broken up into one or more sections have two or morehorizontal bores formed therein. Such housings may be attached to one ormore connect plates.

One of skill in the art will further appreciate that various features ofthe fluid routing plugs, housings, and other components described hereinmay be modified or changed, as desired. While not specifically shown ina figure herein, various features from one or more of the fluid routingplugs described herein may be included in another one of the plugs.Likewise, various features from one or more of the different housingsdescribed herein may be included in another one of the housings.

The concept of a “kit” is described herein due to the fact that fluidends are often shipped or provided unassembled by a manufacturer, withthe expectation that a customer will use components of the kit toassemble a functional fluid end. Alternatively, some components arereplaced during operation. Accordingly, certain embodiments within thepresent disclosure are described as “kits,” which are unassembledcollections of components. The present disclosure also describes andclaims assembled apparatuses and systems by way of reference tospecified kits, along with a description of how the various kitcomponents are actually coupled to one another to form the apparatus orsystem.

The term “means for routing fluid” refers to the various fluid routingplugs described herein and structural equivalents thereof. The term“means for regulating fluid flow” refers to the various suction anddischarge valves and suction and discharge valve guides described hereinand structural equivalents thereof. A “means for pressurizing fluid”refers to the fluid end and the various embodiments of housings andcomponents installed within or attached to the various housingsdescribed herein and structural equivalents thereof.

As used herein, “modular” means an apparatus that is comprised of aplurality of components joined together to form a complete apparatus.Such components may be removable and replaceable with like components,if needed. For example, in some embodiments of the fluid end 100described herein, the fluid end 100 comprises a plurality of fluid endsections 102 joined together to form the fluid end 100. Each fluid endsection 102 may be removed and replaced with a new fluid end section102, if needed.

The various features and alternative details of construction of theapparatuses described herein for the practice of the present technologywill readily occur to the skilled artisan in view of the foregoingdiscussion, and it is to be understood that even though numerouscharacteristics and advantages of various embodiments of the presenttechnology have been set forth in the foregoing description, togetherwith details of the structure and function of various embodiments of thetechnology, this detailed description is illustrative only, and changesmay be made in detail, especially in matters of structure andarrangements of parts within the principles of the present technology tothe full extent indicated by the broad general meaning of the terms inwhich the appended claims are expressed. Changes may be made in theconstruction, operation and arrangement of the various parts, elements,steps and procedures described herein without departing from the spiritand scope of the invention as described in the following claims.

1. A fluid end section, comprising: a housing having a longitudinal axisand opposed first and second surfaces joined by an outer intermediatesurface; a horizontal bore formed within the housing and interconnectingthe first and second surfaces, the horizontal bore extending along thelongitudinal axis of the housing; a discharge bore formed in the housingand interconnecting the horizontal bore and the intermediate surface; anupper intake bore formed in the housing and interconnecting thehorizontal bore and the intermediate surface; a lower intake bore formedin the housing and interconnecting the horizontal bore and theintermediate surface; in which the upper intake bore and the lowerintake bore are collinear; a plunger packing installed within thehousing; a retainer attached to the housing using a plurality offasteners, the retainer having a central passage formed therein; and apacking nut installed within the central passage of the retainer andengaging the plunger packing.
 2. The fluid end section of claim 1,further comprising: a reciprocating plunger disposed within the housing,the retainer, the plunger packing, and the packing nut.
 3. The fluid endsection of claim 1, in which the housing comprises a removable stuffingbox; and in which the plunger packing is installed within the stuffingbox.
 4. The fluid end section of claim 3, in which the stuffing box isattached to the rest of the housing using the plurality of fasteners. 5.The fluid end section of claim 1, in which the plurality of fastenersare threaded studs, the fluid end section further comprising: aplurality of threaded nuts, each nut installed on a corresponding one ofthe threaded studs.
 6. The fluid end section of claim 1, in which theplurality of fasteners are characterized as a first plurality offasteners; and in which the housing comprises a first section joined toa second section by a second plurality of fasteners.
 7. The fluid endsection of claim 1, in which the fluid end section is situated within anambient environment, and in which at least a portion of the retainer isexposed to the ambient environment.
 8. The fluid end section of claim 1,further comprising: a fluid routing plug installed within the horizontalbore and comprising: a body having opposed first and second surfacesjoined by an outer intermediate surface; and a plurality ofnon-intersecting fluid passages formed in the body.
 9. The fluid endsection of claim 1, further comprising: a first annular groove formedwithin the housing and surrounding the horizontal bore, the first groovepositioned between the upper and lower intake bores and the secondsurface of the housing; and a second annular groove formed within thehousing and surrounding the horizontal bore, the second groovepositioned between the discharge bore and the upper and lower intakebores.
 10. The fluid end section of claim 9, in which the first andsecond grooves are each characterized by two side walls joined by and abase.
 11. A fluid end comprising: a plurality of the fluid end sectionsof claim 1 positioned in side-by-side relationship; an upper fluidintake manifold in fluid communication with each upper intake bore ofthe plurality of fluid end sections; and a lower fluid intake manifoldin fluid communication with each lower intake bore of the plurality offluid end sections.
 12. A fluid end, comprising: a plurality of thefluid end sections of claim 1 positioned in side-by-side relationship.13. A high pressure pump, comprising: a power end; and the fluid end ofclaim 12 attached to the power end.
 14. A fluid end section, comprising:a housing having a longitudinal axis and opposed first and secondsurfaces joined by an outer intermediate surface; a horizontal boreformed within the housing and interconnecting the first and secondsurfaces, the horizontal bore extending along the longitudinal axis ofthe housing; a discharge bore formed in the housing and interconnectingthe horizontal bore and the intermediate surface; an upper intake boreformed in the housing and interconnecting the horizontal bore and theintermediate surface; a lower intake bore formed in the housing andinterconnecting the horizontal bore and the intermediate surface; inwhich the upper intake bore and the lower intake bore are collinear; astuffing box attached to the housing by a plurality of fasteners; aplunger packing installed within the stuffing box; and a packing nutattached to the stuffing box and engaging the plunger packing.
 15. Thefluid end section of claim 14, further comprising: a reciprocatingplunger disposed within the housing, the stuffing box, the plungerpacking, and the packing nut.
 16. The fluid end section of claim 14,further comprising: a retainer attached to the stuffing box using theplurality of fasteners; in which the packing nut is installed within acentral passage formed in the retainer.
 17. The fluid end section ofclaim 14, in which the plurality of fasteners are threaded studs, thefluid end section further comprising: a plurality of threaded nuts, eachnut installed on a corresponding one of the threaded studs.
 18. Thefluid end section of claim 14, in which the plurality of fasteners arecharacterized as a first plurality of fasteners; and in which thehousing comprises a first section joined to a second section by a secondplurality of fasteners.
 19. The fluid end section of claim 14, furthercomprising: a first annular groove formed within the housing andsurrounding the horizontal bore, the first groove positioned between theupper and lower intake bores and the second surface of the housing; anda second annular groove formed within the housing and surrounding thehorizontal bore, the second groove positioned between the discharge boreand the upper and lower intake bores.
 20. A fluid end, comprising: aplurality of the fluid end sections of claim 14 positioned inside-by-side relationship.